The Points Based System for immigration is the UK visa system. International students who are non-EU/EEA/Swiss nationals and are applying for entry clearance or leave to remain as a student will usually come under the Tier 4 (General) category.
Student visas - Tier 4 of the Points Based System
Tier 4 Restrictions
Visas - Students applying from outside the UK
Visas - Extending your visa in the UK as a student