Q: Not all of my pics and video are on the cloud,why?

iCloud doesn't store all photos. It only stores the newest one so that they can be synced to other devices.

And if you are referring to Photo Stream, it doesn't store videos at all.

Cheers,

GB

The default iCloud option that is on automatically is My Photo Stream which uploads all of your new photos for up to 30 days to allow your other devices to download them, then they are deleted for the server, but not for your devices.  My Photo Stream FAQ - Apple Support

iCloud Photo Library is another option but it must be turned on manually to upload all of your photos and videos to iCloud: iCloud Photo Library FAQ - Apple Support

If the OP's profile is correct, then iCloud Photo Library is not an option....

My bad - Nevermind.....

Cheers,

GB