"Give me the reason behind while going for sql server other than MS access in so many applications...is there any additional features existing with SQL." <-- an Access database is primarily used for small applications that generally only one computer would use. SQL Server is used when lots of computers need to share the data stored on the databases.
"what do u mean by thread and multithreading?" <-- when you run a program on your computer, it appears as a process. Most processes use a single thread. Which basically means that if you tell the program to do something, it can only do that one command at a time.
Have you noticed that if you some programs, you can tell the program to do one thing and do something completely different on the same program while the previous command still runs? That is multithreading. Being able to do multiple things at the same time.
That's the lamens terms :)
Overloading -> you tell/give the system too much info too quickly to process. The system overloads and, usually, shutsdown/hangs.
Overriding -> eg: a program is designed to do one thing. You come along and tell it to do something it wasn't actually designed for, that's overriding.
Another example is getting into a secure system. This means that you overrode the system's protection.
Hope this helps somewhat, the other stuff I'm not sure on since I don't use it. :)
Look up the term synchronization in
Dictionary.com