The nomenclature of occupations and socio-professional categories (PCS) has been renovated, resulting in a new version, the "PCS 2020". The resulting update at the most detailed level of the "PCS" aims to reflect changes in occupations. The more aggregated levels, corresponding to the socio-professional categories and groups, are unchanged. Socio-professional groups are frequently used to describe employment and the economic and social situations of individuals and households. Thus, in 2021, young people were over-represented among employees and workers. Socio-professional groups are also the classic grid for analysing social mobility: in 2021, more than two-thirds of people aged 35 to 59 changed socio-professional group compared to their parents. The employment classes, new categorisations that complement the "PCS", capture the different inequalities in the duration and organisation of work. Another new categorisation is the "Household PCS", which combines the socio-professional situation of the two main members of the household. It is more relevant than the approach based on the "PCS" of the reference person in the household for analysing certain phenomena, such as housing tenure status; for example, households with a predominantly managerial background have greater access to property.