Why Fritz play so different? which movements to choose Fritz or GM?

I got Fritz and I see that it use differents variations than the common ones. For instances at the beginning of the game he do not use the sicilian or the queens gambit that are the most used by the masters whith d4 or e4, and when the openings continue they do not use quite often the same varition. I want to have one mt?ove, the strongest one, should I choose the one of Fritz or of the masters (I see the game explorer on this page) which one if the best? it is getting me crazy, I want to learn for one or the other at least the main openings. Thanks

Is Fritz using an opening book? If so, blame the opening book, not Fritz. (And it's not even clear to me whether any blame should be placed at all.)

I posted a lucifer-climaxing awesome

explanation but it just whatevered I'm on a

phone anyway Kasparov's loss to Deeper

Blue was fixed nothing, NOTHING beats

human insight. Magnus and them still

keeping it a secret they don't want us to

know how adanced we are as I quote

modern day philosopher Jaden Smith,

"Look around, you'll see."

Hello, it is strange to me, when I start with d4, I see the grandmasters games and almost always continues with c4, however fritz, or chess.com app analizing millions of options do not recomend it. As well when you play against e4, grandmasters normally use sicilian, and this software gives you other options, it something strange for that I do not get to understand. I am going to study gradmasters games, but I am not really convinced. Thank you any way for your anwers

The programmers don't tune the engine to evaluate openings because they know the engine will have an opening book.

Also because calculation is not very useful in the opening, it will take maybe 10 moves before the pieces are fighting and to see 10 moves ahead is impossible to calculate all the variations. It's probably something ridiculously big like 10^12 already.

So for example engines are told to favor the center and piece activity. So many times they will not play the best moves, but simple things like 1.d4 d5 and their next two moves are 2.Nf3 and 3.Nc3. It is not possible to calculate that blocking the c pawn will slow white's middlegame down due to no quick pawn breaks. The engine would need to calculate 10^10 moves per second 

Thank you for your valueable answer, at last I understand!!!  yes it is exactly as you said " So many times they will not play the best moves, but simple things like 1.d4 d5 and their next two moves are 2.Nf3 and 3.Nc3"  now I see I am in the good way and I undertand why because It was breaking my head. THANKS ;.)

It could be paranoia, but I just assumed that he was high on something when he wrote his post.