When searching for an entry, you can specify attributes associated with that type of entry. For example, when you search for people entries, you can use the cn attribute to search for people with a specific common name.
Examples of attributes that people entries might include:
cn (the person’s common name)
sn (the person’s surname, or last name, or family name)
telephoneNumber (the person’s telephone number)
buildingName (the name of the building in which the person resides)
l (the locality in which you can find the person)