Also, note this.
An integrated graphics processing unit (GPU) doesn't use its own RAM; it utilizes the system's memory instead. So, if you have a computer with 4GB of RAM, the video card can use anywhere between one and five percent of the available memory for graphics processing. Of course, this percentage varies depending on the size of task, especially if you're multitasking or playing a game.
These graphics cards don’t generate as much heat or consume as much power, so you can save on battery life. If you use your PC for everyday graphics processing, video editing, and word processing, an integrated GPU is certainly up to the task
A dedicated, or discrete, GPU has its own independent source of video memory, leaving the RAM your system uses untouched. If you have a GeForce GTX 680M video card with 2GB of video memory, for example, that memory is completely separate from your computer's 8GB of system memory. Dedicated cards are perfect if you are into serious gaming or are a professional graphic designer.
Cards such as these are great for hardcore gaming or graphic design. However, dedicated graphics cards do have their drawbacks. Without a compatible design or a good fan, this kind of graphics card can get warm quickly. This card will also be power-hungry and drain your PC’s battery life.