What does accuracy mean?

I got a 93% accuracy? What does that mean? That I made moves that an engine would expect me to make?

I'm just a beginner with a score below 400.

So, I should not pay attention to that value? Because sometimes the value is also very low, even if I won or gained an advantage.

So that's why I feel horrible all the time!

Accuracy (CAPS) is well explained by IM @DanielRensch and has many misunderstandings about how accuracy actually works or what it means. Here is a short video on the topic and great explanation. 

Accuracy is garbage... it's basically what a computer would play if it had 1-2 seconds to think.... The entire post-game analysis peddled by chess.com is garbage because it takes like 10 seconds to process the entire game, which is a complete lie and garbage.

normal people don't need the latest stockfish to tell the difference between a +0.67 position and a +0.81 position

I agree 100%  

I kindly disagree. chess.com "Report" in the game analysis is one of my favorite chess.com features. Is the "10 seconds to process the entire game" that accurate? No, not even close! Does it give a quick "blunder check" and tell me efficiently how solid my game was for the most part? Yes it does. 

If you want a more reliable "accuracy" report on the game, then let the computer run a full report on a higher depth. It will run for about 5 minutes (versus like 10 seconds) and that is much more reliable if that is what you seek.

The chess.com games analysis is just there for u to figure out what u got really wrong and what u did really right, thats about it.

The accuracy score is something u shouldn't pay attention to. I've seen forum posts where people have shown a single chess game having multiple different accuracy score differences just from different people inputting the game in to the analysis. 

Especially for ur rating, just ignore it. use it to find your blunders and analyse those.

I have a question

You know how whenever you play a game against an online opponent, every time you make a move, it shows up in the margin to the right and has a white or black bar with a number beside it. What does it mean?

that means how much time was spent on it i think.

Oh ok thx

But sometimes it is a decimal

You don’t spend an integer amount of second bruh

Does that mean that the engine spent 38.9 seconds (for example) on the move?

No, you/opponent did

No, it's not. It's a valuable tool if you use it intelligently. With a quick analysis after the game it spots your big mistakes easy for you, if you want a deeper analysis...wow guess what... it exists. 

What an absolutely clueless comment.

it's hilarious how your supposed "advantage" disappears completely with your next best move... 10 second analysis is a joke...

The reporting is what it is.  It can help you, but don't let it make you feel bad about your games or your level of play.   Focus on the combinations that you messed up, losing the game or taking a hit you could have avoided, and then see how far back you had to go to avoid it.   If its just a few moves,  then maybe you can learn something from it.   The 'you missed the chance to get a pawn in 23 moves' stuff ... you can't expect to see that and be upset that you did not.