Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
A concurrent programming language lets a program express multiple independent activities and coordinate how they communicate. Those activities may take turns on one processor or execute at the same time on multiple processors. Concurrency describes overlapping progress; parallelism means simultaneous execution. Having concurrency features does not by itself guarantee faster performance.
What makes a programming language concurrent?
In practical terms, a language is concurrent when its language facilities or defined runtime model let a program express multiple independent activities and their coordination. An activity might be a goroutine, a process, or another unit of execution, depending on the language.
Concurrency involves more than starting tasks: a program also needs a way for those activities to communicate or coordinate. The language, runtime, or libraries define how that interaction works. Go’s specification, for example, defines goroutines and channels, while the Java SE 26 Language Specification describes Java as a concurrent language.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsIs concurrency the same as parallelism?
No. Concurrent activities can make progress during overlapping periods without running at precisely the same time. On a single processor, a system can switch rapidly between activities so that they appear to progress together. Parallel activities, by contrast, execute simultaneously, such as on multiple processors.
A concurrent program may run in parallel when hardware and scheduling allow it, but concurrency alone does not promise a speedup. The Go FAQ puts the qualification this way: “concurrency only enables parallelism when the underlying problem is intrinsically parallel.” If a task cannot usefully be divided into independent work, adding concurrent activities may not make it faster.
How do languages provide concurrency?
Languages and their runtimes differ in how they create activities, enable communication, and define synchronization. These examples illustrate distinct approaches rather than a complete taxonomy.
| Language | Documented approach | What it illustrates |
|---|---|---|
| Go | go statements start goroutines; channels communicate values between concurrently executing functions. |
Concurrency and communication can be explicit in the language specification. Go’s guidance also relates its channel approach to communicating sequential processes (CSP). |
| Erlang | Official documentation describes processes as threads of execution and identifies concurrent and distributed programming as central capabilities. | Process-based concurrency can make progress through time-sharing on a single processor. |
| Java | The Java SE 26 Language Specification explicitly describes Java as a “general-purpose, concurrent, class-based, object-oriented language.” | A language’s own specification may classify it as concurrent. |
When comparing concurrency models, useful questions include how activities are created, whether they communicate through shared memory or messages, how synchronization and memory visibility are defined, and how the runtime maps activities onto processors. The answers vary by language and implementation.
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Why do communication and coordination matter?
Independent activities often need to exchange information or avoid conflicting operations. A language’s concurrency model shapes whether this happens through channels, messages, shared memory, synchronization primitives, or other mechanisms. Those rules affect how developers organize work and reason about interactions.
Rank #3
Go’s Effective Go offers this guidance: “Do not communicate by sharing memory; instead, share memory by communicating.” It is a recommendation for Go’s channel-oriented approach, not a universal rule or a claim that Go programs cannot synchronize access to shared data.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Does concurrency make programs safer or faster automatically?
No. Concurrency is a way to structure work, not a guarantee about correctness or performance. Developers still need to account for how activities interact, and parallel execution depends on the problem, available processors, and runtime scheduling. A language’s support makes concurrent designs expressible; it does not make every such design safe or beneficial.
Quick Recap
Best Value
Rank #4
Official references
- Go Language Specification: goroutines, channels, and Go’s concurrency support.
- Erlang/OTP: Concurrent Programming: Erlang processes and concurrency on a single processor.
- Effective Go: Concurrency: Go’s channel-oriented guidance.
- Go FAQ: Concurrency: the distinction between concurrency and parallelism.
- Java SE 26 Language Specification: Java’s language classification.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
