[jamadazi]

It's in contrast to Object-Oriented Programming. In OOP, you define classes of objects, with behaviors/functionality attached to them.

In Bevy, the focus is on the data. The ECS is like a big table (if you are not familiar, you can think of it by analogy with a database or spreadsheet). It stores all your data. Components are like the columns of the table, and entities are like rows.

You then write functionality separately. You can query the ECS to get the data you need. Your logic is not attached to any particular "object instance" or "object type".