what's the difference between x++ and ++x

Answer 1

x++ (x sufix) = you first assign, then increment.
++x (x prefix) = you first increment, then assign.

Answer 2

The former is called pre-increment and later is called post-increment. ++x means first increase the value of x by 1 and then use it. whereas x++ means first use the value of x and then increment it's value by 1. Note: both printf statements are separate not one after other.
https://www.codecademy.com/en/forum_questions/514995a07272221a5b001f32
Now x++ means Increment x after this line and ++x means Increment x before this line. With i++, it's called postincrement, and the value is used in whatever context then incremented; ++i is preincrement increments the value first and then uses it in context