By definition, tennis is an ensemble of skills, which are specific from the point of view of the form and content, mainly focusing on the way one hits the racket and sends the ball on the other side of the net.
Also, it has to do with the way you move on the court, all the activities involved being related to superior nervous activities and to bio-mechanical ones.
The tennis which is played today is very dynamic, complex and there is always something to do better when it comes to techniques and movements.
The more complex a player, the better the game and the higher the performance.
Today, the techniques used are perfectly adapted to the surfaces used and they are more complex and accurate than they used to be.
The speed with which the players hit the ball has increased.
Also, there are different tennis schools and there are different characteristics with each player.
That is why tennis should not be considered a static sport, although the court is smaller than many other kinds of courts.
Every player has a personal style which helps them achieve higher performances and it is very difficult to counter attack another player's style.
Also, it is very difficult for a right-handed to play against a left-handed because everything is reversed, which makes it more difficult for the other one to administrate a situation correctly.
Last but not least, tennis is like some sort of mathematics.
There are different tactics, different calculations which have to be made during a game and therefore, this sport requires intelligence, too.
It is also demanding, but it is a very nice sport.
However, you need years of practice to become a top player and the greatest champions know that.