There are different types of bikini wax you can have, the most common are:
Standard bikini - basic tidy up around the edges of your underwear
Brazilian bikini - a strip left
Hollywood bikini - whole lot off
There are also different types of wax too, some salons will do it with strip wax and some will do it with hard wax, if they are done correctly both techniques are effective for all types of bikini wax.