What does the term Legacy system mean in the computer world?
A "legacy" system is one that is either outdated for most practical purposes, or one that includes older forms of technology. A "legacy-free" PC is one that does not include older ports that would be necessary to support much older equipment, such as parallel ports, ISA slots, serial ports, PS/2 ports, and sometimes even VGA.
To emulate something is to reproduce its functionality or behavior. The goal of emulation is to match the original as much as possible. In computer terms, emulation usually refers to a software application which simulates the functionality of some type of hardware. This commonly takes the form of programs which emulate an older legacy computer or game system. Emulators such as MAME can simulate old cabinet-style arcade machines on modern computer systems. Similarly, software can…
A computer is the physical device, reinstalling is an operation performed on software that is stored on the computer. If you mean reinstalling the operating system for the computer (windows, OSX, linux) , then you should insert the disk for the operating system and then restart the computer and it should guide you through the re-installation process.
Computer organization typically refers to the operational units of the system together with their interconnection. It is this interconnection that realizes the planning specification. The difference between computer organization and architecture is that the latter refers to those attributes of a system that are visible to a programmer.