Beginner question

Positional Chess just means put your pieces in advantageous positions, i.e. rooks and bishops on open files or diagonals funding outpost for your knights, finding safe place for the King, as well as good pawn structure or placing your piece in optimal according placement to the pawns 

Development and space control

Tactics are captures, combinations and mates 

Not playing gambits, aggressive over extending your pawns, and dubious openings.

Good Positional Chess, Planning & Strategy Books for Beginners and Beyond...

https://www.chess.com/blog/RussBell/introduction-to-positional-chess-planning-strategy

Maybe that's how I play. Sorry OP, if this is irrelevant.

"Positional play is prophylaxis" - Nimzovich
https://usuaris.tinet.cat/bttt/escacs/nimzowitsch%20-%20my%20system.pdf 

positional chess is playing the whole game thinking about how the endgame is gonna be

That doesn't even make sense

It means looking for nice places for your pieces.
To positional advantages belongs things like controlling the center of the board, controlling bigger part of the board so your pieces would have more space for maneuver. Having better pawns structure without weak pawns and without some weak holes what could your opponent use as a springboard for his pieces. Overall having active pieces what do attack something or control some important squeres.
It all sounds as a vague description but if you learn how to use weaknesses in the opponent's structere to place your pieces well then you have more oportunities to use some tactics to win some material.

Positional chess is very vast. It can involve big words like planning, strategy, initiative, et cetera. But it all boils down to these two questions you can ask yourself. "What is my advantage in this position, and how can I make use of it?" Doing this, you inadvertently create a plan, something many chess players struggle with.

Above is a random custom position I came up with. White to move has quite a few pieces pointing at Black's weak king, so g4 could be in order. After g4, White notices he has a nice square on d6 for his knight, so he can play Ne4 and put it there. 

Black to move has a material advantage (he's an exchange up) and when you are up material you should trade pieces. So Nxc3! bxc5 Qd5! forces a queen trade and Black is simply winning.

1st word lol

"Positional chess is playing the whole game thinking about how the endgame is gonna be."

That covers a lot of it!

For example, ensuring that your pawns are on opposite colors of the bishop you end up with is an example of positional play.

Pawn structures with a knight can also be advantageous in a knight vs bishop endgame.

Keeping the bishop pair in an open position is another example of a positional strategy.

This goes very deep.

All in all it means that you consider the entire state of the board at all times, and not just short-term gains. In that sense, yes, positional chess is much more prophylactic.

It's like a war; rather than targeting a single platoon or focusing on one tactical sequence, you are aware of what's going on in all sections of the battlefield.

The entire game sort of feels like an army of spiders slowly creeping up on the enemy king, constricting his space until he runs out of breath. Rather than going for that devastating blow.