There are immigration laws a person must follow in the United States if they wish to become a citizen. It may be necessary to seek an immigration lawyer in certain circumstances. For example if the government wishes to deport you an immigration lawyer can review your case and make an argument for you to stay. Typically an immigration lawyer is going to help you fill out the proper paperwork to get you into a country and become naturalized. Only qualified personnel can act as an immigration lawyer.
The lawyer you choose must be well versed in immigration law regarding the country you wish to live in, such as the United States. The immigration lawyer does have a fee they normally charge for their services.