The sum of skills (basic and new basic skills) needed to live in contemporary knowledge society.
Source: CEDEFOP 2008, Europe

Any of several generic skills or competencies considered essential for people to participate effectively in the workforce. Key competencies apply to work generally, rather than being specific to work in a particular occupation or industry. The Finn Report (1991) identified six key areas of competence which were subsequently developed in the Mayer Report (1992) into seven key competencies: collecting, analysing and organising information; communicating ideas and information; planning and organising activities; working with others and in teams; using mathematical ideas and techniques; solving problems; and using technology.
Source: NCVER 2013, Australia

Key competences are:
1) Communication in the mother tongue;
2) Communication in foreign languages;
3) Mathematical competence and basic competences in science and technology;
4) Digital competence;
5) Learning to learn;
6) Social and civic competences;
7) Sense of initiative and entrepreneurship;
8) Cultural awareness and expression.
These key competences are all interdependent, and the emphasis in each case is on critical thinking, creativity, initiative, problem solving, risk assessment, decision taking and constructive management of feelings.
Source: EU Legislation 2007, Europe

The application of universal knowledge and skills across a range of social, work, and geographical settings (Comment: Key competences are also referred to as critical cross-field outcomes, transferable skills and core competences)
Source: UNESCO 2015, Global