Can sombody help me?

Question

I didnt understand increment and decrement! Can sombody explain it?

Answer 1

increment
$×=1;
$×++; is the same as $× = $× + 1;

decrement
$x=1;
$x--; is the same as $×= $× -1;

Answer 2

It is short for increasing or decreasing an arithmetic value by 1,

this is post increment:
$a = 1;
$a++;

this is pre-increment:
++$a;

same with decrement, just replace ++ with --