To makes moves increasing our mobility at the expense of the opponents so we can finally make a move creating two threats , where only one can be dealt with. This I believe is where the concept of tactics meets strategy, because at the simplest level, a twin threat is a fork...I had come to this conclusion before seeing it expounded in a well known tactics book.
What is the underlying essence of strategy in chess?.

Strategy encompasses all aspects of play so I am not sure we can speak of "the essence of strategy". Attacking the uncastled King via the e file,creating favorable positions for your Bishop pair,attacking the castled king,knowing when and what to exchange,playing with/against an isolated pawn,minority attack,weak squares,outposts,theory of two weaknesses,transition to endgame,etc.etc. you realize therefore that the essence of strategy...is to have done your homework with regard to each and every strategical theme...
Thank you. Do you know the meaning of the words ''underlying essence'' in the sentence above ''what is the underlying essence of strategy''?.

the essence of strategy is to checkmate the opponent...everything else is a distraction.
Thank you. So, It's simple as that, I thought It's hard to understand, but you forgot to put the word ''underlying'' in your sentence.

I think it is possible to answer the OP's question succinctly in a serious manner:
Strategy is the struggle between structure and dynamism.

I think it is possible to answer the OP's question succinctly in a serious manner:
Strategy is the struggle between structure and dynamism.
Very nicely said indeed!

I think it is possible to answer the OP's question succinctly in a serious manner:
Strategy is the struggle between structure and dynamism.
Thank you. So, do you know the meaning of the words ''underlying essence'' in the sentence above ''what is the underlying essence of strategy''?.

What is the underlying essence of strategy in chess?.
Games like shown in the thread below:
Games played with feeling; essence; lots of blunders but lots of brilliant moves (specially by me).

I should like to add that I consider Wilhelm Steinitz,Akiba Rubinstein,Mikhail Botvinnik and Vladimir Kramnik four prime examples of Great chess Strategists.

My goodness Marco... you are the first person I have seen to advertise a post
LOL !! That is why I trully believe my thread is wonderful!!
Then I am going to advertise again:
Games like shown in the thread below:
http://www.chess.com/forum/view/game-analysis/the-most-interesting-game-of-chess-was-played-here-in-chesscom
Games played with feeling; essence; lots of blunders but lots of brilliant moves (specially by me).

Strategy is the fight over all of the units that cannot be counted in pawns or pieces.
Tactics are there, or they aren't,
but there is always a way to improve your position.

Tactics is the underlying essence of any sort of strategy in chess, including checkmating the enemy king.
The tactics that could potentially result in favor of one player or another dictate the moves that end up being made, so they are the underlying force or inherent nature of all that we choose to do in chess, when we are making moves that serve the right purpose toward a winning game.

Tactics is the underlying essence of any sort of strategy in chess, including checkmating the enemy king.
The tactics that could potentially result in favor of one player or another dictate the moves that end up being made, so they are the underlying force or inherent nature of all that we choose to do in chess, when we are making moves that serve the right purpose toward a winning game.
Thank you. So, the meaning of the words ''underlying essence'' is the ''inherent nature''.

the underlying essence of strategy in chess is to control more of the important squares than your opponent controls. which squares are important is determined by pawn structure and piece placement.
Thank you. So, do you know too what is the meaning or other words for the words ''underlying essence''?.
Strategy encompasses all aspects of play so I am not sure we can speak of "the essence of strategy". Attacking the uncastled King via the e file,creating favorable positions for your Bishop pair,attacking the castled king,knowing when and what to exchange,playing with/against an isolated pawn,minority attack,weak squares,outposts,theory of two weaknesses,transition to endgame,etc.etc. you realize therefore that the essence of strategy...is to have done your homework with regard to each and every strategical theme...
Just to quibble a bit, but those are mostly tactics. To parapharse what I've read elsewhere: "create positonal advantage to gain material advantage, then use the material advantage to gain a winning positional advantage". Taking advantage of blunders that lose material, you can sometimes skip the first part.
In my opinion Strategy encompasses tactics.Dynamic play and static play are parts of Strategy(tactical and positional if you prefer).So tactics could be seen as one of the many elements of Strategy and not its "opposite" if you like.