Tactics are often associated with winning material through a combination or attack, so you could think of concepts such as trapping an opponents queen or blundering a knight are more tactical in nature. Other ideas, like discovered check, pins, decoys, etc are primarily tactical as well. Many lower level games are decided by tactics simply because players are more apt to fall into traps, not calculate properly, etc.
Strategic play is much more subtle, but becomes more important as you get stronger. Strategic play generally involves more long term planning with the goal of creating a lasting advantage for yourself. Some examples of strategic concepts are creating more space for yourself (and at the same time constricting your opponent), having a better pawn structure (e.g your opponents pawns are isolated and vulnerable to attack), having your minor pieces better positioned(e.g your bishops rake open diagonals while your opponent's are trapped behind pawns)
Not particularly good at chess, but could the difference be likened to the following:
Tactics - winning pieces or losing fewer than your opponent
Strategy - putting yourself in a position where the above is more likely to happen or be possible
?
In chess, tactics are usually shorter term moves that aim to gain material advantage or mate. Pins, skewers, discovered check, forks, double attacks, etc. These are usually in a time frame of around 2-3 moves. This is often described in chess terms as 'concrete' threats.
Strategy concerns more of theoretical ideas, long term possibilities. 10+ moves ahead. This involves pawn structure, where your king is positioned, how your pieces are developed, which side of the board left or right you might launch an attack, end game considerations, etc. How you intend to defend or win the game. This type of play is usually called positional. Whereby the placement of your pieces gives you an overall advantage. In GM level play this is very subtle and 15+ moves ahead. Positional vs. tactical.
As an analogy tactics are like cobra strikes and positional play is like a boa constrictor where tiny shifts strangle the opponent in the end. Both are lethal.
strategical: I wonder if I can machinate to end up mostly on white squares by the end-game, then I could let his black bishop take this pawn for free, while I work on getting my pawn structure to become invincible on the other side, effectively nullifying his bishop by the end-game while opening my position for greater pressure.
tactical: how can I protect this pawn, together with the rest of my pieces, so that all lines in the next 15 moves have all pieces protected, so that he can't take anything, and defensive enough that he can't force a 'better position' in any of them, while remaining offensive enough to open up for a future attack.
Strategy refers to overarching objectives that will direct the larger part of your moves throughout the game.
IE - Knowing your opponent is aggressive with their queen and having plans in place to quickly neutralize her,
or being good at manipulating your opponents pieces util it gets to a point where you can gain a strong advantage by castling.
All these objectives form the basis of what you're trying to accomplish with the ideal being that successfully executing your major objectives will gain you victory.
Tactics refers to how well one reacts to and overcomes changes on the board.
IE - Based on the current board layout you notice that a certain move(s) will heavily fortify a section of the board that you previously were not focused on, or seeing your opponent set up for a particular pattern of play you feint a reaction only to hit them somewhere else.
As a tactical player he focuses more on evolving his strategy(larger objectives) to fit the board rather than trying to manipulate the board to fit his strategy more so than the average chess player.
tactical: calculating the right moves in complex situations. strategical: positional play. making sure the pieces work well together, choosing the right plan and so on
