Since the beginning of Scratch, block categories have provided a user-friendly way of accessing desired blocks. Blocks are categorized based on their functionality, and blocks within the same category share the same color. The separation of color among categories can allow better distinction of the parts of a project, as well as increase the ease of access. The following are the block categories as of Scratch 2.0:
- Main article: Motion Blocks
Motion blocks deal with the movement of sprites. They relate mainly to the x and y position and direction of the sprite, as almost all the blocks correspond to them. The Stage does not contain any Motion blocks since it is a still object.
- Main article: Event Blocks
Events blocks are related to various triggers in a project, or when one part signals another to run. The Events blocks used to be part of the Control category prior to Scratch 2.0. The "Events" category consists mostly of hat blocks.
- Main article: Looks Blocks
- Main article: Control Blocks
Control blocks run the basic flow of a project in a desired fashion, whether it be organized or unexpected. They provide functions for looping various blocks and scripts. They "control" the project and enhance its running.
- Main article: Sound Blocks
Sound blocks are related to playing various sounds, whether they be MIDI notes or saved sounds.
- Main article: Sensing Blocks
Sensing blocks associate with sprites and the stage detecting conditions. For example, sensing blocks can be used to detect when one sprite touches another. They consist of many booleans and can work with Control blocks to stabilize a project' a flow.
- Main article: Pen Blocks
Pen blocks are related to a sprite's pen, which is a feature that allows a line to be to be drawn in accordance with a sprite's location (the line or "pen" is always at the costume center of the sprite it is in). The blocks are associated with turning the pen on and off, stamping a sprite's image onto the stage, and adjusting the various appearance values of the pen.
- Main article: Operators Blocks
Operators blocks, originally called "Numbers" blocks, deal with many mathematical functions within a project. They are a green color and provide the capabilities of simple to complex mathematical operations. "Operators" also contains blocks for modifying strings and implementing them into various uses. There are some boolean blocks, too, in which some are related to mathematical outputs, while others are used for adjoining other booleans into one or a different output condition.
- Main article: Data Blocks
Data blocks include two subcategories, Variables and Lists, but both are related to storing and accessing data. Prior to Scratch 2.0, this category was called "Variables". Data blocks are used for storing information, such as a score in a project, and using it in scripting and other beneficial purposes.
Lists are another subcategory of Data blocks. The blocks become visible once a list is created.
- Main article: More Blocks
More blocks are blocks that hold custom procedures for a selected sprite. The blocks are useful for running a script without screen refresh and organization of the scripts.
- Main article: PicoBoard Blocks
PicoBoard blocks is a subcategory of the More Blocks.
- Main article: LEGO WeDo Blocks
LEGO WeDo blocks is another subcategory of the More Blocks.