A "CAT 3 - General ticket" can be situated anywhere within the CAT 3 level in Philippe Chatrier court. The CAT 3 level is generally situated in the upper half of the second level of the stadium and still offers decent views onto Center Court.
Cat 2 - General tickets are located in the first 10-15 rows of the upper level. The CAT 2 level seats offer very good views onto center court. You can access all the outside courts with your ticket.
A "CAT 1 - General ticket" can be situated anywhere within the CAT 1 level of Philippe Chatrier. The CAT 1 level is situated just above the CAT Or level which can be from 2 to 12 rows off the actual court, depending on the Tribune.