Images for web will need to be small and accessible to all.
To ensure that everyone can see the images the best practice is to save the images as jpegs with a maximum resolution of 1920 pixels wide by 1080 pixels high which is what works on laptops. (The images can be smaller than that but should not be larger for best practices.)
Why?
Saving this way will ensure all users can see the work to collaborate even with slower internet.
This is best practices as you start your role as a media designer for the web.
Export> Save for Web (legacy) from Photoshop:
Step one: shortcut =
Command Option Shift S on a mac
or
Control Option Shift S on a PC
Then make sure the image is being saved as a JPEG High 60 quality is good
with optimized checked
with converted to RGB checked
Image size within 1920 x1080 or smaller
then save