There are a number of ways to search for names on the website:
Surname + first name i.e Smith John
Surname + service number i.e Smith 45320
All these methods will bring up a list of any record with these details, with the specific one requested at the top of the list. Searching by surname will result in a list of all those with the surname followed by all other records who have the name included. However, the first names will not be in alphabetical order hence Smith Thomas may appear ahead of Smith Joseph. With common surnames, searching by service number, if known, would be more beneficial in producing the correct individual. You can also search by regiment or by memorial name.