Tier 5 is for Temporary workers – Government Authorised Exchange Visa.

Tier 5 can be used by immigrants who want to come to the UK for a short time for work experience or to do training, an Overseas Government Language Programme, research or a fellowship through an approved government authorised exchange scheme.

In order to qualify for the Tier 5 there is a need of sponsorship from licensed sponsor.
The work, training or research in the UK must relate to the work of your sponsor organisation.