Welcome to Android Central! Those 8.3 GB are taken up by the OS and preinstalled bloatware (that you can't get rid of). The OS itself usually takes about 3-4 GB of storage, and unfortunately, some manufacturers and carriers load phones with lots of useless junk that take up even more space.
The internal storage media in your Android device is going to be divided into several partitions. Most of those partitions are dedicated to the operating system, and one is set aside as the user data partition. All those system partitions are restricted and any files and folders residing on them will be protected by system-level permissions. That user data partition however, where all your files, data, and whatever are stored, is not restricted. You, the user, have complete, open access to anything on that one partition so any files and things have only loose, user-level permissions.
So don't even waste your time trying to free up storage capacity by 'cleaning' those system partitions. You simply don't have any real access to them. They're managed and maintained by the installed Android operating system, you're essentially locked out. Instead focus on the files and things you do have control over. Delete apps you're previously installed but no longer use. If you have a microSD card move as much of your photos, videos, music, etc. as you can from the internal storage to the card. Or you need to get a phone with more internal storage capacity.
Just keep in mind, you only have the ability to manage the user storage space, the system storage space is off-limits.
Hello. I am currently using a LG tribute royal with a total of 14g space. In the internal storage section it says that 8.3g is used for system. I tried to clear cache but it did not work. I tried to clear the cache of the system but it is not working.