RS-232 (Recommended Standard 232, also known as EIA/TIA RS-232C) is an interface that designates a standard for the exchange of a series of binary data between a DTE (Data Terminal Equipment) and DCE (Data Communication Equipment , Data Communication Equipment), although there are others in which the RS-232 interface is also used. An equivalent definition published by the ITU is called V.24. The RS-232 is a connectorDB-25 type (25-pin), although it is normal to find the version of 9-pin (DE-9, or popularly also called DB-9), cheaper and even extended to certain types of peripherals (such as serial mouse PC).

Parallel cable is the cable for computers defined by the IEEE 1284 standard for connecting peripherals via the parallel port. It is often used for connecting printers compatible PC computers. It is considered an outdated connection and has been replaced by USB. - IEEE 1284 Type A: 25-pin DB-25 IEEE 1284 - IEEE 1284 Type B: 36 Drivers, Champ type Centerline Connector 0.085 insurance (Centronics). - IEEE 1284 Type C: 36 conductors, connector type mini Champ de Centerline 0.050 with secure clip (mini Centronics).

SCSI, acronym for Small Computers System Interface (Small Computer System) is a standard interface for transferring data between devices on the bus of the computer. Types of SCSI SCSI one. 8-bit, 50-pin. Maximum length 6 meters Fast SCSI 2. 8 bits, 50 pins. Maximum length 3 meters Wide: 16-bit, 68-pin high density. Maximum length 3 metersUltra SCSI 3: 16-bit, 34-pin. Maximum length 1.5 meters. Ultra Wide: 16-bit, 68-pin. Maximum length 1.5 meters Ultra 2: 16-bit, 68-pin high density. Maximum length 12 meters.

English stands for Enhanced Parallel Port serious. It is a communication method for bi-directional parallel between the PC and peripherals, offering speed ratios and much higher than traditional transfer methods for parallel transfer. EPP is not for printers, however ECP is mainly for printers and scanners. It is part of the IEEE 1284 standard.

SPP correspond to Standard Parallel Port. It belongs to the IEEE 1284 protocol and serves to create a Bidirectional Parallel Peripheral Interface for PCs. It is a protocol that is compatible with all PC devices unlike ECP and EPP.