Buffer Definition: A buffer is an area of memory (RAM) reserved for temporary storage. For instance, you've probably noticed that you can quickly type a bunch of commands on the keyboard, and then just sit back and watch your computer carry out the commands one after another. This is because the computer stores the keys you pressed in a buffer-after doing one command; it goes back to the buffer to get the next one in line.
Some programs use the term buffer to refer to the space reserved in memory for the information of a file you're working with. Actually, you can start a new buffer and put information in it before you save it on disk as a file, but the idea is that the buffer represents a collection of information in memory that is handled as a unit.
For example, when you press several keys in quick succession on the keyboard, the commands are stored momentarily in a buffer, allowing the computer to process them in the correct order.
Printers, modems, and other devices can have buffers too. If your printer doesn't have a buffer, your computer can only send it a little information at a time, as much as the printer can output immediately. With a buffer, the computer can send a document at full speed, at least until the buffer fills up. The information waits in the buffer until the printer is ready to print it, but meanwhile you can go back to work with your computer.
In DOS, the word buffer refers specifically to the small buffers reserved for DOS's use when transferring information to or from a disk. DOS buffers are a crude kind ofdisk cache;when information is available in a buffer, it doesn't need to be re-read from the disk, and your system operates faster. DOS automatically sets up a standard number of buffer capacity (usually 15), but you can change buffer capacity by entering a command such as BUFFERS=20 in your CONFIG.SYS file. Why do this? Because, up to a point, the more buffer capacity there are, the faster the system will run (although there's no practical way to figure out the ideal number of buffers). On the other hand, if you are using a true disk cache such as SMART Drive or Super PC-Kwik, DOS buffers are redundant, wasting memory and actually slowing things down. In this situation you should always set the number of buffers to 3 or 4.