Padel is very similar to Tennis. The rules are the same as in tennis, the strokes are similar. In Padel you use the Forehand ground stroke, the Backhand ground stroke and of course the Volley. It is easy to learn if you know how to play tennis because in Padel you use the same grips, you can slide the ball and most of the movements are the same.The big difference are the back walls made mostly of glass where you have a second chance to hit the ball.
Squash is a high-speed racquet sport played by two players (or in doubles 4 players on court at a time) in a four-walled court with a small, hollow rubber ball. It is fast and it requires mental agility.
Padel is similar to Squash when it comes to the glass walls. The ball may strike the side or back walls at any time, as long as it hits the ground first. Then is when you can hit the ball again and it is one of the greatest aspects of this fun racquet sport.
To view the similarities you can what this video.