I use this which updates 2 of my drivers per day for free:
http://www.drivermax.com/--------------------
My attempt at explaining drivers: Your computer is made up of physical parts called hardware. These pieces hardware are made up of circuits that switch on and off, processing 1's and 0's. These 1' and 0's make up binary numbers, numbers in base 2. With the right circuits, we can now form the logic needed to make a process number in bases that are multiples of 2. For example, hex, which is in base 8. Now, we can combine these hex and binary numbers into bit strings and store the bit strings in memory. The bit strings can then be read back and processed as a low level programming language, known as assembly.
Now, keeping track off all of these low level 1's and 0's is hard, which is why we have made content management systems for our computers, known as Operating Systems. Example operating systems: Mac OS, Windows, Linux
Now, wait a second....we skipped something. How the hell can an operating system manage a computer's lower level functions when every computer is built differently with different hardware...and often even different assembly languages. We can not expect for an operating system to simply know how to talk to all of your computer's parts right off the bat, can we? No.
This is where drivers come in. Drivers are mini low level programs that act like mediators between your operating system and the hardware.
Now, imagine you are the leader of your country. An alien race comes down from outer space to make friends with you, but you do not know each other's language. In order to get around this, you heir a college professor to observe / study the alien race, so that the professor can translate for you. As time goes by, the professor is going to get better and better at translating.
The same concept goes with drivers and their updates. The longer a piece of hardware has been on the market, the better computer scientists (such as myself) are going to get at making more efficient drivers for that piece of hardware, and driver updates are going to come out. This updates since they are more efficient often help to speed up communication between your operating system and the hardware that the driver is for.