Can someone explain this to me in Simple Words?

Question

In-place operators allow you to write code like 'x = x + 3' more concisely, as 'x += 3'.
The same thing is possible with other operators such as -, *, / and % as well.

Answer 1

x = x+3 is same as x +=3 and similar with other operators like x %=3 or x *= 3 etc. as well.