These are vocational awards in England and Wales that are achieved through assessment and training. In Scotland they are known as Scottish Vocational Qualification (SVQ). 
There are five levels of NVQ ranging from Level 1, which focuses on basic work activities, to Level 5 for senior  management.

NVQ level 1

foundation GNVQ OR three to four GCSEs at grades D-E OR Business & Technology Education Council (BTEC) first certificate

NVQ level 2

five GCSEs at grades A*-C OR BTEC first diploma

NVQ level 3

two or more A levels, BTEC Ordinary National Diploma (OND), City & Guilds Advanced Craft 

NVQ level 4 

BTEC Higher National Certificate (HNC) OR Higher National Diploma (HND), OR a First Academic Degree (BSc, BA, BEng or other academic degree). 

NVQ level 5

postgraduate qualification or higher degree, such as MSc, MA, MEng. or PhD