What does overclocking mean in graphic cards?

Answer 1

A processor (graphic processor for your case) has different function stages and upon completeing all necessary stages, its consider as once cycle, then it goes through the same thing again and again, cycle after cycle.

Frequency is the number of cycle in a second, reflecting how fast the processor is running. (the more cycle you run in a second, the faster each cycle runs)

Generally, overclocking means increasing the frequency, increasing the speed the processor. In graphic card, you're increasing the graphic processor speed, usually refere to as "core speed" or "core frequency".

The memory on the graphic card has its own frequency too, so you can tweak with this frequency too. It's called "memory frequency".

This can be easily done with overclocking software, but of course there's limit to how fast you can increase the frequency of your graphic card processor and memory before the hardware start to malfunction.

Answer 2

Its both a speed gain and a heat gain, typically the speed is about a 20% increase and the heat can vary

Answer 3

overclocking means it is overheating so you need to put more ventilation on it or more air supplie
or just get a new video card to handle what ever it is your running

Answer 4

it means to increase the GPU speed and/or the memory speed.