A register is a set of data or information that documents important events in a particular context. This could be a legal register, a database of property ownership, or an official list of voters in an election. The word also appears in computer systems as a small, fast storage unit that plays an essential role in processor performance by temporarily holding instructions and data during processing.
The term is often used in the context of point-of-sale systems and cash registers, where it refers to a place where items are priced, totals calculated, payments processed, receipts issued, and other transaction-related activities take place. In retail settings, a register is also used to document the location of inventory and track stock changes. Similarly, the register may refer to a computer system that is used by loan servicers to track repayment schedules and other borrower information.
In computing, a register is a small and fast storage location within the central processing unit (CPU) or arithmetic logic unit that temporarily holds data during processing. Its size, speed, and capacity vary by CPU design. Registers are often organized into a hierarchy, with the highest-speed registers located in cache memory between the CPU and main memory. This strategy exploits the principle of temporal locality, storing frequently-accessed data closer to the CPU for faster access than would be possible with main memory alone.
There are multiple types of CPU registers, including model-specific registers, internal registers, and architectural registers. Model-specific registers store data and settings specific to a particular processor design, which is why they do not usually persist across processor generations. Internal registers store data and information that is not directly accessed by instruction sequences, and the instruction register holds the currently-executing CPU instruction. Architectural registers, which are visible to software, are defined by a processor’s architecture, and they can sometimes be duplicated for better performance via hardware-based techniques such as register renaming or speculative execution.
Registering can mean putting one’s name on an official list in order to participate in an activity or receive a service. In the United States, people who wish to vote must register with the local elections office. Thousands of people line up to register to vote in an election. A register can also be a collection of records or data, such as an account of property ownership, or a list of names and ages.
The word can also be used in a legal sense to refer to a formal record maintained by an authority, such as a land register or court record. For example, a county, town, or state government may maintain a register of deeds that lists all real estate transactions and ownership transfers. Similarly, the term can also refer to a public listing of those who have applied for a passport or a driver’s license. These examples have been automatically selected and may contain sensitive content. Please use discretion when sharing this article.