Can someone tell me how to categorize my pictures

Use albums in the Photos app to view and organize your photos and videos.

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Create a new album

1. Tap Albums at the bottom of the screen.
2. Tap. , then choose New Album.
3. Name the album, then tap Save.
4. Tap the photos you want to add to the album, then tap Add.

Use albums in Photos on iPhone - Apple Support (IN)