The Standard Occupational Classification, often abbreviated as the SOC, is the system used by the United Kingdom's Office for National Statistics (ONS) to classify people for statistical purposes according to their job. Under this system, a job is defined as "a set of tasks or duties to be carried out by one person".[1] The SOC classifies jobs according to the level and specialisation of skill.[1] The SOC was introduced in 1990.[2] It has undergone several revisions; the latest, SOC 2020, includes nine major groups of occupations, each broken down into smaller units: there are 26 sub-major groups, 104 minor groups and 412 unit groups.[1] The groups are designed to be as similar as possible to the International Standard Classification of Occupations 2008.[1]