Hi, i want to know about domain expiration. i did buy a domain before 1 year in 10$. now it is gonna be expire in 20 days. my question is if i will not renew domain it will be expired what happened. domain will completely expired or i could recharge any time after expiration. some domain provider makes you fool because they don't give you domain authority so how to know i have full authority of domain. please help me i am very confused.
If your domain expires in 20 days, after that 20 days , based on the registrar, it will have a grace period (0-45 days) and redemption grace period (30 days). Depending on the registrar, during these periods, the domain can still be renewed. After this period, it will be in pending delete period (5days) and then it is deleted and available for registration for others. Take a look at the attached picture to get an idea. I am not sure what you mean by 'some registrars not giving domain authority'.
If you didn't get full authority or access to manage your domain name, that might mean you were registering domain name with Reseller while not accredited Registrar, you can check the whois information and find who is your Registrar. If you were saying gTLDs like .com, .net, than I would totally agree with nhed about the time cycle of domain renewal/redemption/deletion. If you were saying some ccTLDs like .es, than I am afraid you will have to renew the domain name before the expiration date as ccTLD like .es don't have renewal grace period.
As a rule of thumb always keep your domain registration separate from your hosting to ensure you have full control. Don't let it expire - your site will go offline and your reputation will be damaged. If the registrar is charging too much suck it up this time and transfer away asap - although this will incur an extra year's registration too. Registration fees for a single domain are tiny, just get it done.