@Stephen *******
the Uk visit visas has an expiry date of one year from being issued. You can enter the country as many times as you like but can only stay a maximum of 6 months in any one visit.
The visit visa can also be issued for 2,5,10 years. You have the option to choose. But the same process as the 1 year visa you can only stay a maximum of 6 months each time you enter the Uk