Entry clearance & immigration regulations：
首先，所有关于英国的签证均是由UK Visas and Immigration（UKVI）来审理，我们来看一下UKVI的官方定义：
Entry into the UK is managed by UK Visas and Immigration (UKVI). The UKVI points based visa and immigration system (PBS) is designed to be objective and transparent, and give students the peace of mind that the courses they are applying for are run by bona fide institutions approved by the UK government. Immigration regulations are subject to change on a regular basis.
大意就是UKVI是负责审理一切英国签证和移民事务，PBS是类似于用来给每一份签证申请人打分的一个系统，，英国的签证旨在为每一个来到英国学习的个体一个最平和的思想和学习环境；同样，移民的政策和主旨也并非一成不变的。
作为国际留学生，我们接触的最普遍的就是学生签Tier 4（General）student visa和短期访问学习签证SVV了。
以下便是Tier 4官方简介：
You can apply for a Tier 4 (General) student visa to study in the UK if you’re 16 or over and you:
have been offered a place on a course;
can speak, read, write and understand English;
have enough money to support yourself and pay for your course - the amount will vary depending on your circumstances;
are from a country that’s not in the European Economic Area (EEA) or Switzerland;
meet the other eligibility requirements
要点：16岁或以上可申请general student签证；如果年龄在4-16岁，那么签证类型就是Tier 4(child)；
达到英语的要求，这里一般是按照学校课程要求的雅思成绩；
提供可以支付学费和生活费的存款证明（具体存款金额多少，存款怎么存，欢迎小窗咨询咖咖酱）
EEA（欧连体）和瑞士等国家的公民，不需要签证