concurrently

Concurrently is an adverb meaning existing or occurring at the same time. It originates from the adjective concurrent, which in turn derives from Latin concurrere "to run together". In general usage, it describes events that overlap in time, such as two meetings that take place concurrently.

In computing, concurrency refers to the ability of a system to manage multiple tasks that progress over overlapping time periods. Tasks may be interleaved on a single processor or executed in parallel on multiple processors. Concurrency aims to improve responsiveness and resource utilization, for example by handling user input while performing background operations or by processing several network requests at once.

Common programming approaches to achieve concurrency include multi-threading, asynchronous programming with non-blocking I/O, and event-driven architectures. Each approach introduces synchronization challenges, such as race conditions and deadlocks, which are addressed with mechanisms like locks, mutexes, semaphores, and atomic operations.

Concurrently contrasts with parallelism. Parallelism denotes true simultaneous execution on multiple processing units, while concurrency emphasizes overlapping progress, which may or may not be truly parallel depending on hardware. In many systems, concurrency and parallelism are combined to maximize efficiency.

Examples: The server handles requests concurrently. Two components operate concurrently during the startup phase.