What is an engine

What beat Kasparov in 1997.
It's a chess algorithm.
Today's (AlphaZero, Leela, Stockfish) are absolutely unbeatable.

engines are computers to calculate moves, to understand more, you can scroll down in where you find bots, then you will find something called engine, this is an example of engine, oh yes the bots it self is an example of engine, strong engines are stockfish 15 and alphazero

The top engines are so strong that even Super GMs need to start with a two pawn advantage against them

0/10 for that answer.

It's a computer program that could calculate every possible move and variation up to a very limited depth, but not as limited as humans in the same time scale. In practice it doesn't;  many variations are pruned to make the depth less limited (but still very limited).

It can partially order the moves according to a questionable evaluation function. Unless there is a forced mate or stalemate within the depth to which it calculates or the position is covered by an appropriate endgame tablebase to which the engine has access, the best moves in the resulting partial order may or may not be theoretically correct, but if played against humans will usually result in a win for the player using the engine moves. 

If the engine uses the UCI (Universal Chess Interface) protocol, the player using the engine moves would usually be another piece of software called a GUI (Graphical User Interface). You play the GUI rather than the engine in that case. It could also be someone cheating on chess.com or an ICCF player (who is allowed to cheat).

Engines calculate about 20 moves ahead in every variation, so if you can think deeper than that, then you'll easily beat them.

My first chess engine was embedded in a GUI with state of the art graphics. Wikipedia calls it a video game. It ran on a DOS computer with 1 MB RAM. The "good old days"!

Now my chess software has several analysis engines installed.

@AussieMatey #10

Indeed, in simple positions with few men on the board you can quite often outperform engines if you have studied the endgame enough. I can outperform any engine in White to win positions and most drawn positions in KNNKP for example.

On the other hand in Black to win KNNKP positions or drawn positions where the pawn cannot be prevented from queening or captured on the queening square SF14 would probably draw the majority of the former if I played Black and win the majority of the latter if I played White, because I haven't spent a deranged amount of time studying those positions.

SF14 can in most such positions that are winning for either side play not just perfectly, but perfectly accurately, up to a depth of at least 30 moves.

Although that depth no doubt rapidly diminishes in closely matched positions as you add extra men beyond five, human play deteriorates faster. It is an experimental fact that humans will usually lose against SF14 from the starting position playing either colour.