What does a visit visa let me do?

In short, a visit visa lets you study an accredited short course, get medical treatment, enjoy tourism, have meetings or do research. But you cannot work, marry or use it to live in the UK. You need a TB test and the £95 fee. There are also versions for 2, 5 or 10 years, but they may need quite some proof that you are not planning to live in the UK, you do not get a refund if refused, and of course any visa can be curtailed if the Home Office become suspicious, so it may be better to build up an immigration record of compliance with 6 month visas first. You cannot switch or extend a normal visit visa. Any visit visa needs an explanation of why you are visiting and why you will leave. You will have to declare dates, places, earnings, criminal record and trip costs, and maybe employment and travel history. There are special rules for academics and medical treatment.