The modem converts digital signals from the computer to analog signals and send them over the telephone lines to the Internet server. At the other end another modem connected to the server converts the analog signal back to digital signals and vice versa. A conventional CD-ROM can accommodate about 650 MB of data. The speed at which data can be read from the CD-ROM depends on the speed at which the disk spins in the drive. Printers Printers print the data stored in your files on to paper.
Printers are of different types and include dot matrix, ink jet and laser printers.
DPI refers to the print quality and ppm to the printing speed. Scanners Scanners convert photographs and other printed material into digital form. In the digital form these converted photographs and graphics can be manipulated in a variety of ways using application software. Though these are the basics, you won t have to look heavenwards next time someone talks about computers.