Unit 2 Vocabulary

Unit 2 Vocabulary

Control Flow

Control Flow: The order in which a program’s instructions run. Conditionals and loops change the flow.
Conditional: Code that runs only when a condition is true. In Scratch, the if … then and if … then … else blocks.
Condition: A yes/no question a program asks, such as touching [ground v]? or (score) = (10). It is always either true or false.
Boolean: A value that is either true or false.
Boolean Operator: A block that combines or flips booleans: and, or, not. See Boolean Operators.
Loop: Code that repeats. forever repeats until the project stops; repeat (10) runs exactly ten times; repeat until < > runs until a condition becomes true.
Iteration: One pass through a loop.
Game Loop: A forever loop with if blocks inside it that checks what is happening every frame. Almost every game runs on one.
Flow Diagram: A picture of a program’s steps and decisions, drawn with ovals, rectangles, and diamonds. See Flow Diagrams.
User Input: Anything the player does that the program can react to — key presses, mouse clicks, clicking a sprite.

Variable: A named container that holds a value, like score or lives. The value can change while the program runs.
set: Replaces a variable’s value with a new one. Use it to reset.
change: Adds to a variable’s current value. Use a negative number to subtract.
Velocity: How fast something is moving in a direction. In our platformer, a positive velocity moves the sprite up and a negative one moves it down.
Gravity: A constant pull downward. We simulate it by changing velocity by a small negative number every frame.
Acceleration: A change in velocity over time. Falling faster and faster is acceleration.

Collision Detection: Checking whether two sprites overlap. Scratch uses the touching block and the visible pixels of each costume.
Hitbox: The part of a sprite that counts for collision. In Scratch it is the non-transparent pixels of the costume.
Platform: A surface the player can stand on or jump to. Many platforms drawn on one costume still count as one sprite.
Step-Up Test: A wall-collision technique: after moving sideways and touching something, move up a few pixels and check again. If still touching, it was a wall.
Clone: A copy of a sprite created while the program runs. Each clone runs the when I start as a clone script on its own and should end with delete this clone.
Clone Factory: The original, hidden sprite that creates clones on a timer.
Broadcast: A message one sprite sends that every sprite can hear with when I receive. Used to switch game states.
Game State: Which part of the game the player is in — start screen, playing, game over, paused.
Remix: Your own editable copy of someone else’s shared Scratch project.
Studio: A collection of shared projects on Scratch. See Share to the Class Studio.

Last updated on October 7, 2026