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Session (computer Science)
In computer science and networking in particular, a session is a time-delimited two-way link, a practical (relatively high) layer in the TCP/IP protocol enabling interactive expression and information exchange between two or more communication devices or ends – be they computers, automated systems, or live active users (see login session). A session is established at a certain point in time, and then ‘torn down’ - brought to an end - at some later point. An established communication session may involve more than one message in each direction. A session is typically stateful, meaning that at least one of the communicating parties needs to hold current state information and save information about the session history to be able to communicate, as opposed to stateless communication, where the communication consists of independent requests with responses. An established session is the basic requirement to perform a connection-oriented communication. A session also is the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, applied disciplines (including the design and implementation of Computer architecture, hardware and Software engineering, software). Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of computational problem, problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and preventing security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Phone
Voice over Internet Protocol (VoIP), also known as IP telephony, is a set of technologies used primarily for voice communication sessions over Internet Protocol (IP) networks, such as the Internet. VoIP enables voice calls to be transmitted as data packets, facilitating various methods of voice communication, including traditional applications like Skype, Microsoft Teams, Google Voice, and VoIP phones. Regular telephones can also be used for VoIP by connecting them to the Internet via analog telephone adapters (ATAs), which convert traditional telephone signals into digital data packets that can be transmitted over IP networks. The broader terms Internet telephony, broadband telephony, and broadband phone service specifically refer to the delivery of voice and other communication services, such as fax, SMS, and voice messaging, over the Internet, in contrast to the traditional public switched telephone network (PSTN), commonly known as plain old telephone service (POTS). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTTP Cookie
HTTP cookie (also called web cookie, Internet cookie, browser cookie, or simply cookie) is a small block of data (computing), data created by a web server while a user (computing), user is browsing a website and placed on the user's computer or other device by the user's web browser. Cookies are placed on the device used to access a website, and more than one cookie may be placed on a user's device during a session. Cookies serve useful and sometimes essential functions on the World Wide Web, web. They enable web servers to store program state, stateful information (such as items added in the shopping cart in an Online shopping, online store) on the user's device or to track the user's browsing activity (including clicking particular buttons, access control, logging in, or recording which Web browsing history, pages were visited in the past). They can also be used to save information that the user previously entered into Form (HTML), form fields, such as names, addresses, passw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object (computer Science)
In software development, an object is an entity that has state, behavior, and identity. An object can model some part of reality or can be an invention of the design process whose collaborations with other such objects serve as the mechanisms that provide some higher-level behavior. Put another way, an object represents an individual, identifiable item, unit, or entity, either real or abstract, with a well-defined role in the problem domain. A programming language can be classified based on its support for objects. A language that provides an encapsulation construct for state, behavior, and identity is classified as object-based. If the language also provides polymorphism and inheritance it is classified as object-oriented. A language that supports creating an object from a class is classified as class-based. A language that supports object creation via a template object is classified as prototype-based. The concept of object is used in many different software contexts, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thread (computer Science)
In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system. In many cases, a thread is a component of a process. The multiple threads of a given process may be executed concurrently (via multithreading capabilities), sharing resources such as memory, while different processes do not share these resources. In particular, the threads of a process share its executable code and the values of its dynamically allocated variables and non- thread-local global variables at any given time. The implementation of threads and processes differs between operating systems. History Threads made an early appearance under the name of "tasks" in IBM's batch processing operating system, OS/360, in 1967. It provided users with three available configurations of the OS/360 control system, of which Multiprogramming with a Variable Number of Tasks (MVT) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Child Process
A child process (CP) in computing is a process created by another process (the parent process). This technique pertains to multitasking operating systems, and is sometimes called a subprocess or traditionally a subtask. There are two major procedures for creating a child process: the fork system call (preferred in Unix-like systems and the POSIX standard) and the spawn (preferred in the modern (NT) kernel of Microsoft Windows, as well as in some historical operating systems). History Child processes date to the late 1960s, with an early form in later revisions of the Multiprogramming with a Fixed number of Tasks Version II (MFT-II) form of the IBM OS/360 operating system, which introduced ''sub-tasking'' (see task). The current form in Unix draws on Multics (1969), while the Windows NT form draws on OpenVMS (1978), from RSX-11 (1972). Children created by fork A child process inherits most of its attributes, such as file descriptors, from its parent. In Unix, a child pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Web Page
A dynamic web page is a web page constructed at runtime (during software execution), as opposed to a ''static web page'', delivered as it is stored. A server-side dynamic web page is a web page whose construction is controlled by an application server processing server-side scripts. In server-side scripting, Parameter (computer programming), parameters determine how the assembly of every new web page proceeds, and including the setting up of more client-side processing. A client-side dynamic web page processes the web page using JavaScript running in the browser as it loads. JavaScript can interact with the page via Document Object Model (DOM), to query page state and modify it. Even though a web page can be dynamic on the client-side, it can still be hosted on a static Web hosting service, hosting service such as GitHub Pages or Amazon S3 as long as there is not any server-side code included. A dynamic web page is then reloaded by the user or by a computer program to change som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Gateway Interface
file:Common Gateway Interface logo.svg, The official CGI logo from the spec announcement In computing, Common Gateway Interface (CGI) is an interface specification that enables web servers to execute an external program to process HTTP or HTTPS user requests. Such programs are often written in a scripting language and are commonly referred to as ''CGI scripts'', but they may include compiler, compiled programs. A typical use case occurs when a web user submits a web form on a web page that uses CGI. The form's data is sent to the web server within a HTTP request with a URL denoting a CGI script. The web server then launches the CGI script in a new computer process, passing the form data to it. The CGI script passes its output, usually in the form of HTML, to the Web server, and the server relays it back to the browser as its HTTP response, response to the browser's request. Developed in the early 1990s, CGI was the earliest common method available that allowed a web page to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Session ID
In computer science, a session identifier, session ID or session token is a piece of data that is used in network communications (often over HTTPS) to identify a session, a series of related message exchanges. Session identifiers become necessary in cases where the communications infrastructure uses a stateless protocol such as HTTP. For example, a buyer who visits a seller's website wants to collect a number of articles in a virtual shopping cart and then finalize the shopping by going to the site's checkout page. This typically involves an ongoing communication where several webpages are requested by the client and sent back to them by the server. In such a situation, it is vital to keep track of the current state of the shopper's cart, and a session ID is one way to achieve that goal. A session ID is typically granted to a visitor on their first visit to a site. It is different from a user ID in that sessions are typically short-lived (they expire after a preset time of inact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTTP Cookie
HTTP cookie (also called web cookie, Internet cookie, browser cookie, or simply cookie) is a small block of data (computing), data created by a web server while a user (computing), user is browsing a website and placed on the user's computer or other device by the user's web browser. Cookies are placed on the device used to access a website, and more than one cookie may be placed on a user's device during a session. Cookies serve useful and sometimes essential functions on the World Wide Web, web. They enable web servers to store program state, stateful information (such as items added in the shopping cart in an Online shopping, online store) on the user's device or to track the user's browsing activity (including clicking particular buttons, access control, logging in, or recording which Web browsing history, pages were visited in the past). They can also be used to save information that the user previously entered into Form (HTML), form fields, such as names, addresses, passw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
User Datagram Protocol
In computer networking, the User Datagram Protocol (UDP) is one of the core communication protocols of the Internet protocol suite used to send messages (transported as datagrams in Network packet, packets) to other hosts on an Internet Protocol (IP) network. Within an IP network, UDP does not require prior communication to set up communication channels or data paths. UDP is a connectionless protocol, meaning that messages are sent without negotiating a connection and that UDP does not keep track of what it has sent. UDP provides checksums for data integrity, and port numbers for addressing different functions at the source and destination of the datagram. It has no Handshake (computing), handshaking dialogues and thus exposes the user's program to any Reliability (computer networking), unreliability of the underlying network; there is no guarantee of delivery, ordering, or duplicate protection. If error-correction facilities are needed at the network interface level, an applica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
