I actually mean playing poker professionally,like taking part in tournament's,etc.
Do you think that it is considered all across the world as gambling?
No. Poker is a skill game. But it can be gambling if you want it to be. Just go all in every hand.

So do you think that a skill-based game that involves money is not a gambling, and gambling is only about all in? If so, you are wrong. Gambling is something that make us to risk our money in order to get some profit imho, so playing poker is also a gambling activity unless you play it without money.