MIT's drag-and-drop visual programming language — instead of typing syntax, you snap together color-coded blocks like puzzle pieces. It's the single most common first-programming-language experience in the world, used in classrooms from elementary school onward.
Everything in Scratch happens to a sprite (a character or object) sitting on the stage (the screen). Each sprite has its own independent stack of blocks that controls what it does.
Every script starts with a yellow "hat" block that says when it runs.
These snap around other blocks like a physical container — a repeat block literally wraps around the blocks it repeats.
Made in the Variables palette, then dragged into other blocks — no typing a declaration the way you would in a text language.