COBOL

COBOL, in fullCommon Business-Oriented Language., High-level computer programming language, one of the first widely used languages and for many years the most popular language in the business community. It developed from the 1959 Conference on Data Systems Languages, a joint initiative between the U.S. government and the private sector. COBOL was created to fulfill two major objectives: portability (ability of programs to be run with minimum modification on computers from different manufacturers) and readability (ease with which a program can be read like ordinary English). It ceased to be widely used in the 1990s.

Data structure

Data structure, way in which data are stored for efficient search and retrieval. Different data structures are suited for different problems. Some data structures are useful for simple general problems, such as retrieving data that has been stored with a specific identifier. For example, an online dictionary can be structured so that it can retrieve the definition of a word. On the other hand, specialized data structures have been devised to solve complex specific search problems.

The simplest data structure is the one-dimensional (linear) array, in which stored elements are numbered with consecutive integers and contents are accessed by these numbers. Data items stored nonconsecutively in memory may be linked by pointers (memory addresses stored with items to indicate where the “next” item or items in the structure are located). Many algorithms have been developed for sorting data efficiently; these apply to structures residing in main memory and also to structures that constitute information systems and databases. More-complex data structures may incorporate elements of simpler data structures.