What types of invitation letters does the UAE have, and what are they used for?

The UAE generally has business visit invitation letters, work visa invitation letters, and family visa invitation letters. Business visit invitation letters are used for investors coming to the UAE for inspections or short-term business negotiations. Work visa invitation letters are used by companies to apply for work visas for their employees, allowing them to work legally in the UAE. Family visa invitation letters are used by employees to apply for visas for their family members to reunite in the UAE. (Adam)