A register is a special form of storage inside a computer processor that holds data and instructions for immediate processing. It is made up of flip-flops and contains a limited amount of data ranging from 8 to 64 bits depending on the CPU architecture. Registers enable quick manipulation of data and reduce the need to access main memory frequently enhancing computer processing efficiency. The term can also be used to describe a document that records past events, transactions or names in an organized fashion. The word can also be used as a verb meaning to make something clear and visible, such as when voters wish to register their dissatisfaction with the ruling party.
Almost all computers, whether they have load/store architecture or not, use registers for intermediate storage of items being processed. They are manipulated or tested by machine instructions and then stored back in main memory, either by the same instruction or by a subsequent one. Almost all modern processors have both static and dynamic random-access main memory, which is often accessed via cache levels that store copies of frequently used data.
The amount of information that can be contained in a register depends on the type of computer and its architecture, but most have some combination of data, address and general purpose registers. Data registers can hold numeric data values such as integers and, in some processor architectures, floating-point numbers. They can also contain characters and small bit arrays. Address registers are used to store the addresses of memory locations for instructions that indirectly access primary memory. In addition, some CPU architectures include special function registers that correspond to specialized hardware elements such as the program counter or stack pointer.
In accounting, a register can be used to document individual financial transactions or a more comprehensive record of financial transaction types as defined by account categories such as cash receipts and payments. The term can also be used to describe an organization’s database of shareholders and their holdings in a company.
Registers are used in most jurisdictions to track property ownership and transactions. These registers are typically maintained at the local, town, city or state level and may be accessed by the public for various purposes including researching titles to properties. These registers can also be used to maintain a history of ownership for a particular property, allowing it to be transferred from one person to another. A registry is also sometimes referred to as a land title or deed record. This record can be viewed by anyone, and is generally accessible for free at local office or courthouse libraries. A register can also be used to keep a record of the transactions and owners of automobiles, motorcycles or other vehicles. These records can be accessed by vehicle registration authorities in most jurisdictions. A car dealer can also keep a record of the owners of their cars, using a registration or vehicle log book. This can help with determining the value of a car when it is sold or traded.