A Category is the next level of organization in Layer under Projects.
Categories contain Elements and Fields .
You can think of a Layer Category as analogous to a tab in a spreadsheet - it should contain distinct fields (columns) and separate elements (rows) from the other categories. Elements and Fields are restricted to a single category and cannot be copied between categories. Like tabs in a spreadsheet, categories contain very little information outside of the structure of their Elements , the real home of your data in Layer. You can have an unlimited number of Categories in your project.
New categories should be created for managing new data types. If you would use a new tab in a spreadsheet to organize your data, you should probably create a new category. If you find yourself recreating fields from one category to another or wishing they could be copied, you likely could be using the same category.
<aside> 💡 If you’re summarizing similar types of data, an additional category can be used to provide a higher level of abstraction between related pieces of data. For more information, see Category Relationships.
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Creating and Managing Categories