If you would like to invite friends or family members for a short visit to the UK, your visitor should apply for a Standard Visitor visa.
To qualify for this visa type, your visitor must show:
• that they wish to visit the UK for no more than six months;
• that they intend to leave the UK at the end of the visit; and
• they have enough money to support themselves while they are in the UK without working or having recourse to public funds.
If your visitor is a non-visa national they do not need to apply for immigration permission before travelling to the UK as they will apply for entry to the UK at the border by showing the same documents as they would if they were applying for a visa from overseas.
Check the UKVI website to find out whether your visitor must apply for their visa before travelling to the UK or whether they can apply on arrival.