Silly question about MP Pocket Players Handbook


I just know that this is a silly question but I don't yet own the D&D Players Handbook for 3.5 (I don't play Dungeons and Dragons) but I wold like to pick up the Mongoose Publishing Pocket Players Guide(Handbook).
Are these basically the same thing? Or do they contain different rules?
I need to purchase a players handbook for my B5 game (I know B5 is 3.0) but figured I would rather give my money to Mongoose than WOTC.

Any help?
The Pocket book is basically the same as the PHB, but concentrateson straight rules, rather than fluff, examples, art, etc. You can indeed use the Pocket book with B5.