Concept of Buffers

In computing, a buffer is a region of memory used to temporarily hold data while it is being moved from one place to another. Typically, the data is stored in a buffer as it is retrieved from an input device (such as a keyboard) or just before it is sent to an output device (such as a printer). However, a buffer may be used when moving data between processes within a computer.
Buffering is used to improve several other areas of computer performance as well. Most hard disks use a buffer to enable more efficient access to the data on the disk. Video cards send images to a buffer before they are displayed on the screen (known as a screen buffer). Computer programs use buffers to store data while they are running. If it were not for buffers, computers would run a lot less efficiently and we would be waiting around a lot more.
Buffers are another way that receivers can ensure that they do not miss any data sent to them. Buffers can also be useful on the transmit side, where they can enable applications to work more efficiently by storing data to be sent as the link is available.
The buffers may be in hardware, software, or both. When the hardware buffers aren't large enough, a PC may also use software buffers, which are programmable in size and may be as large as system memory permits. The port's software driver transfers data between the software and hardware buffers.
In micro controllers, the buffers tend to be much smaller, and some chips have no hardware buffers at all. The smaller the buffers, the more important it is to use other techniques to ensure that no data is missed.