BleepingComputer.com: What is the meaning of video card in the laptop?

If laptop has 128 shared memory then how can I increase if I have total 512 MB.Is video card related to games?

The video card is related to games, the graphical component of the software is sent to the video card instead of being done at the CPU. Most laptops use integrated graphics, that means the chips doing the processing are physically soldered onto the motherboard and cannot be removed or upgraded. Laptops that have discrete graphics, a card whose processing core and memory are confined to the card, are also not removable. If the video card uses shared memory, it utilizes the main system memory (RAM) instead of chips that are dedicated solely to the video card. For instance, if the shared memory the video card uses is 128MB and the PC has 512MB of RAM, then the total amount of RAM available to the system is 384MB after the video card gets its share. Some newer laptops alter the amount of memory to be used by the video card if more RAM is installed.