The system unit is an element that protects the internal parts of the computer from damage and maintains the desired temperature inside the case. Usually, a system unit is a collection of all devices installed inside the case.
The system units are based on the following materials: aluminum, plastic and steel. This applies to the serial production of computer cases. Plexiglas or wood are sometimes used to improve system units. A standard system unit is designed to fit a certain type of motherboard. This facilitates the process of choosing a case for a computer and installing the necessary equipment in it. Modern system units have a large number of their own ports. The most commonly used ports are USB, headphone jacks, microphone jacks and various memory cards. Naturally, the standard case contains slots for connecting DVD drives, indicators of the hard drive and buttons for turning on and restarting the computer. A motherboard is installed inside the system unit. It is to it that all other computer devices are subsequently attached. The power supply is attached separately from the motherboard. This device has an AC port. It provides voltage to all internal computer equipment. Usually, additional fans are installed inside the case of the system unit. Their purpose is to ensure the optimum temperature inside the block. This is necessary to prevent overheating of the internal devices by constantly blowing air from the outside. The sizes of system blocks can be very different. If we are talking about nettops, then the cases of these computers outwardly resemble a small Wi-Fi router. There are vertical and horizontal types of system units. The classic dimensions for the BigTower format are 190 × 482 × 820. Sometimes you can find cases with dimensions 173 × 432 × 490 or 533 × 419 × 152 (horizontal block).
