Official Financial Sponsor
The UK Border Agency (UKBA) definition of an Official Financial Sponsor can be found in the UKBA Tier 4 Policy Guidance document available on the UKBA website - Tier 4 students - documents required (external site) . The definition is as follows:
'A student may be sponsored by an official financial sponsor. An official financial sponsor is Her Majesty's Government, the student's home governement. the British Coucil or any international organisation, international company, university or UK independant school.'
An official financial sponsor is not a friend or family member.
If you are sponsored by an official financial sponsor, you must show evidence of this when making your Tier 4 visa application.
Please read the Tier 4 Policy Guidance document avialable in the link above to ensure the evidence you show meets the requirements.