Definition - What does Buffer mean?
A buffer is a temporary holding area for data while it's waiting to be transferred to another location. It is usually located in the RAM. The concept of the buffer was developed in order to prevent data congestion from an incoming to an outgoing port of transfer.
There are common uses for the buffer that help improve a device's overall performance. Nearly all hard disks make use of a buffer to facilitate easy retrieval of data. Any type of memory handling and data storage service will make use of some sort of buffer as well. Even the CPU's most basic tasks need to use buffers to operate in the form of registers, where data like operands and operators are stored before they are processed.
Techopedia explains Buffer
For example, when a user downloads a video or audio file, a certain percentage of the downloaded file is placed in the buffer and then played. As the clip is played, the device continuously downloads the file and places it in the buffer. Because of this, there is less chance that the video or audio file will stall when network congestion occurs, unless of course the download rate is so slow that the play speed catches up with it.
As another example, when printing a document, when the PRINT command is invoked by the system or the application, the print data is sent to the buffer and is then transferred to the printer. From there, the printer accesses the information. This frees the computer up to do other tasks while the PRINT command is being performed. One disadvantage to this system is that any data in the buffer during device failure is lost.