Jump
A jump is the most basic and most ambiguous wallriding tech. When most people use the word “jump” they mean any kind of wall jump you can perform. This means it is irrelevant what kind of wall jump you do, anything's fine. “Jump” is also often times used interchangeably with “Skim” - the next tech we will cover.
Execution
To perform a jump just go to a wall and press jump twice. You can hold the first jump input as long as you want, but you have to do the 2nd one in the maximum 0.2 seconds allotted for a wall jump.
The first jump input will attach you to the wall, starting a wallride. This wallride will be held until a wall drop-off is initiated by either turning a corner too fast or releasing the jump key. This will put you I the state for a wall jump for roughly 0.2 seconds. Doing the 2nd jump input in that time frame will make you perform a wall jump. Omitting the 2nd jump input will just make you fall down.
Pros and Cons
Jumps have some advantages and one major downside. First of all, they're incredibly easy to do, making them very consistent. They're also faster than just wallriding, allowing you to beat 90% of surf players with one single tech. However, their massive speed loss at high velocities due to holding onto the wall before jumping off make them a poor choice for anything but the first jump of two. They also having a limited jump length, due to the wallriding.