To better understand how conditionals and loops work, open a new project in Scratch, and build the following code:
Once you complete this code, try to add three more IF/THEN blocks and keyboard control in all four directions (up, down, left, and right). The IF/THEN blocks are conditionals. The block inside of it will only work if the condition (e.g. key pressed) is true. If the key is not pressed, the block in the IF/THEN block will not work, or the condition is not met. All of these conditionals are inside of a FOREVER block, or a loop. This allows them to be executed at any time once the program is running. For more information, watch the videos below: