Meaning of 3 colored dots in the upper left of iOS apps

Can you please provide a screenshot of what you are seeing? This will make it much easier to understand what you are asking. I'm also guessing that you are referring to iOS 26, not iOS 2.

Are you referring to the Window Control buttons? This is only on iPads on iPadOS 26, not iPhone.

If so, they are used to close, minimize, and maximize an app window.

You can read more about Window Control here:

Work with multiple windows at once on iPad - Apple Support (VN)

Learn the meaning of iPhone status icons

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