I recently applied for this huge company about two months ago and was just curious to know is their hiring process normal. Everyday I would check my status of the application and nothing will change. One particular day my status was not selected. Therefor I thought I didn't get the job. But two weeks later I received a phone call stating that I have a interview with the HR. IS this normal? Do HR really update the statuses online, because now I am confused??!
What is normal is that systems are often out of sync, data gets updated or not, processes fail.
If you have an interview, go to the interview and ignore what the web page status says. What matters is what people say, not a web site status. No matter what the web site says, you don't have the job until you've been offered the job and given a starting date.
Here are some things to explain the mismatch: someone was supposed to update the status, and they updated the wrong one; they updated it incorrectly; they're on vacation and didn't make the changes; something else that it is not possible to know. It doesn't matter how big or small the company is. A level of disorganization is completely normal, and it is sometimes visible and sometimes not.
It also doesn't do any good to try to figure out why it doesn't match. You were offered an interview, so go to the interview. It's probably not even worth bringing up the mismatch in the interview, because it really doesn't matter.
Big companies often have hiring managers operate pretty independently from the HR team, and the systems they use aren't always well integrated. It's entirely possible that one hiring manager saw your application and wasn't interested, so your status updated, then another saw it and was interested and therefore you get scheduled for an interview. Don't overthink it. :)