As you may have noticed, there are usually several ways to do the same thing in Photoshop. Opening files is no exception!
From your computer’s filing system
Right-click on any image file and select ‘Open With‘. Choose Photoshop from the options listed.
Photoshop files (with the .psd extension) and RAW files can be opened by double-clicking on them.
If you attempt to open RAW files directly in Photoshop, they will first be opened in Adobe Camera RAW (ACR). Once you have completed any edits in ACR, click the Open button at the bottom right of the ACR screen. If you wish to open the image as a Smart Object, either select ‘Open as Object’ from the dropdown or hold SHIFT and click Open.
Photoshop File menu
Click File >> Open and navigate to the file you want to load.
Photoshop maintains a list of recently opened files. Click File >> Open Recent and select from the list. The number of files which appear can be set in Preferences >> File Handling.
Lightroom
If you use Lightroom, you can send files directly to Photoshop. Right-click on the image in Lightroom and select ‘Edit in Photoshop‘.