Tips & Definitions:
Software engineering is the profession that creates and maintains software applications by applying technologies and practices from computer science, project management, engineering, application domains, and other fields. Software is the programs and data that direct computers to perform useful work. Complex software applications can be found in every aspect of modern life from life-critical medical-monitoring devices and nuclear power plants to entertainment video-games, from space missions to microwave ovens. Many software products contain millions of lines of code that are expected to perform properly in the face of changing conditions. Software generally needs to be reliable (with the consequences of failure ranging from annoying to deadly) and needs to be produced economically. Software engineering aims to address these needs. Software engineering techniques are intended to improve the functionality and reliability of software, while improving the efficiency and easing the task of software development. The SE community includes 630,000 practitioners and educators in the U.S. and an estimated 1,400,000 practitioners in the E.U., Asia, and elsewhere; it is about 60% the size of traditional engineering. SE pioneers include Barry Boehm, Fred Brooks, C. A. R. Hoare, and David Parnas. There is extensive debate about what SE is, who qualifies as an SE, who sets the standards, etc.

Programming languagesMain article: programming language A programmer writes source code in a particular programming language. Different programming languages support different styles of programming (called programming paradigms). Part of the art of programming is selecting one of the programming languages best suited for the task at hand. Different programming languages require different levels of detail to be handled by the programmer when implementing algorithms, often resulting in a compromise between ease of use and performance (a trade-off between "programmer time" and "computer time"). The only programming language a computer can directly execute is machine language (sometimes called "machine code"). Originally all programmers worked out every detail of the machine code, but this is hardly ever done anymore. Instead, programmers write source code, and a computer (running a compiler or an interpreter or an assembler) translates it through one or more translation steps to fill in all the details, before the final machine code is executed on the target computer. Even when complete low-level control of the target computer is required, programmers write assembly language, whose instructions are mnemonic one-to-one transcriptions of the corresponding machine language instructions. In some languages, an interpretable p-code binary (or byte-code) is generated, rather than machine language. Bytecode is used in the popular Java programming language by Sun Microsystems as well as the Microsoft's recent .NET family of languages.

Software licenses are primarily written to deal with issues of copyright law and product liability law. Sometimes the license touches on issues of patent law, trade secret law, and laws pertaining to access to services. Software licenses generally fall into two categories, proprietary software licenses and free software licenses, depending on the purpose of the license. Free software licenses grant additional rights (such as the ability to copy) and need not be accepted to use the software, while proprietary EULAs seek to restrict the user's actions, and require that the user 'signs-up to' the license. Software licenses tend to work in conjunction with software source code escrow agreements. This article deals primarily with the licenses of proprietary software distributed in the United States of America. Open source software licenses are treated in a separate article. See also: Uniform Computer Information Transactions Act, Legal aspects of computing EULAs and shrink-wrapping Most end user license agreements (EULAs) accompany shrink wrapped software that is presented to a user sometimes on paper or more usually electronically, during the installation procedure. The user has the choice of accepting or rejecting the agreement. The installation of the software is conditional to the user accepting the agreement and thereby agreeing to abide by its terms. Some computer companies view the EULAs more as an elaborate liability disclaimer than a real contract. It is not uncommon for a user to be unable to read the license before proceeding with starting up a computer they have just bought (which the computer might require on an on-screen message), because no printed copy of the license is included. Users almost invariably click on "Accept" without reading the license. EULAs can often contain very restrictive terms that are often surprising. For example, the version 7 of a popular image-viewing application ACDSee prohibits its use for viewing pornographic materials in the EULA (section 3.4 - Use Restrictions). It is unclear whether EULA licenses are enforceable in the United States (see shrink wrap contracts).