Scratch is were you make animations and video games by using code blocks,they are simple but you have to use them right or the game wont work, also in scratch you can post the games you have made. and play games that other people have made,and like them too.
algorithm is what you tell the computer to do and it will do it so if you say move ten steps on sprite 1 then it will move ten steps.
debugging is when there is a problem in the game it an be a big problem or a small problem in the code and you fix it. one time when i did this is when i when i was making my helicopter game the helicopter was not changing costume and i had to fix it because it was really bugging me so i did hide costume and it worked the helicopter crashed! i did well on the movement of the helicopter and controlling it however, i need to add more cave for the heli copter and i think that will improve the game,also the animations of the helicopter crashing could improve.i like using scratch it is fun and it leads to your imaginatio of what you can do.