Domain and hosting are two different things
Many people think that domain and hosting are the same thing, but they are not. The domain is the address (porositweb.com), while hosting is the place where the files are stored. You can change them independently of each other.
How to change hosting without losing your domain
Buy a new hosting plan from the new provider
Transfer the website files to the new hosting
Change the Name Servers (DNS) on your domain to point to the new hosting
Wait 24-48 hours for DNS propagation
Verify that everything is working correctly
What you should watch out for
Take a full backup before starting the transfer
Do not cancel the old hosting until everything is working on the new one
Check the email — if the email depends on the hosting, ensure it is functioning
Inform the new hosting provider about any active SSL certificates
Conclusion
The domain is your property and does not obligate you to stay with the same host. If you are not satisfied with the speed or support, feel free to change — the domain comes with you.