Databases in the context of SQL

Software consists of computer programs that instruct the execution of a computer. Software also includes design documents and specifications.

The history of software is closely tied to the development of digital computers in the mid-20th century. Early programs were written in the machine language specific to the hardware. The introduction of high-level programming languages in 1958 allowed for more human-readable instructions, making software development easier and more portable across different computer architectures. Software in a programming language is run through a compiler or interpreter to execute on the architecture's hardware. Over time, software has become complex, owing to developments in networking, operating systems, and databases.

A union catalog is a combined library catalog describing the collections of a number of libraries. Union catalogs have been created in a range of media, including book format, microform, cards and more recently, networked electronic databases. Print union catalogs are typically arranged by title, author or subject (often employing a controlled vocabulary); electronic versions typically support keyword and Boolean queries. Union catalogs are useful to librarians, as they assist in locating and requesting materials from other libraries through interlibrary loan service. They also allow researchers to search through collections to which they would not otherwise have access, such as manuscript collections.

The largest union catalog ever printed is the American National Union Catalog Pre-1956 Imprints (NUC), completed in 1981. This achievement has since been superseded by the creation of union catalogs in the form of electronic databases, of which the largest is OCLC's WorldCat. Other examples include K10plus in Germany, Library Hub Discover (formerly COPAC) provided by Research Libraries UK and AMICUS, provided by Library and Archives Canada.

Information access is the freedom or ability to identify, obtain and make use of database or information effectively.

There are various research efforts in information access for which the objective is to simplify and make it more effective for human users to access and further process large and unwieldy amounts of data and information.

In physical security and information security, access control (AC) is the action of deciding whether a subject should be granted or denied access to an object (for example, a place or a resource). The act of accessing may mean consuming, entering, or using. It is often used interchangeably with authorization, although the authorization may be granted well in advance of the access control decision.

Access control on digital platforms is also termed admission control. The protection of external databases is essential to preserve digital security.

A computer language is a formal language for humans to communicate with a computer, not a natural language. In earlier days of computing (before the 1980s), the term was used interchangeably with programming language, but today, used primarily for taxonomy, is a broader term that encompasses languages that are not programming in nature. Sub-categories (with possibly contended hierarchical relationships) include:

• Construction
  • Programming – for controlling computer behavior
    • Command – for controlling the tasks of a computer, such as starting programs
    • Query – for querying databases and information systems
    • Transformation – for transforming the text of a formal language into text that meets a specific goal
  • Structural
    • Configuration – for writing configuration files
    • Data exchange – examples: JSON, XML
    • Markup – for annotating a document in a way that is syntactically distinguishable from the text, such as HTML
    • Page description – for describing the appearance of a printed page in a higher level than an actual output bitmap
    • Style sheet – for expressing the presentation of structured documents, such as CSS
• Modeling – for designing systems
  • Architecture description – for describing and representing system architecture
  • Hardware description – for modeling integrated circuits
• Simulation – for simulating
• Specification – for describing what a system should do

In metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. Data elements usage can be discovered by inspection of software applications or application data files through a process of manual or automated Application Discovery and Understanding. Once data elements are discovered they can be registered in a metadata registry.In the areas of databases and data systems more generally a data element is a concept forming part of a data model. As an element of data representation, a collection of data elements forms a data structure.