How do you delete photos on your computer?

From where are you deleting them from?

If from your Photos Library use the key combination of ⌘+Delete to move them to the Recently Deleted album. They will be automatically deleted after 3o days. Or you can go to that album and complete the deletion immediately.

If the photos are in folders on your hard drive just drag them to the Trash bin in the Dock and empty it.

If the photos are managed by the Photos.app, you can select it in Photos in the browser and use the keyboard shortcut ⌘⌫ to delete photos. They will be moved to the Recently Deleted album, where they will be automatically deleted after thirty days.

When you are viewing photos in the predefined albums created by Photos you can use the command "Image > Delete Photo" to delete selected photos. While viewing and album you created yourself, you need to hold down the command key ⌘ to make the "delete photo" command visible.Otherwise you are only seeing "remove from album".