This idea of **asynchronous** code described above is also sometimes called **"concurrency"**. It is different from **"parallelism"**.

**Concurrency** and **parallelism** both relate to "different things happening more or less at the same time".

But the details between *concurrency* and *parallelism* are quite different.

To see the difference, imagine the following story about burgers:

### Concurrent Burgers

  // be less than this number when ((.spec.completions - .status.successful) < .spec.parallelism),
  // i.e. when the work left to do is less than max parallelism.
  // More info: https://kubernetes.io/docs/concepts/workloads/controllers/jobs-run-to-completion/
  // +optional
  optional int32 parallelism = 1;

  // Specifies the desired number of successfully finished pods the

    /**
     * ProjectBuilder parallelism.
     *
     * @since 4.0.0
     */
    @Config(type = "java.lang.Integer", defaultValue = "cores/2 + 1")
    public static final String MAVEN_MODEL_BUILDER_PARALLELISM = "maven.modelBuilder.parallelism";

    /**
     * User property for enabling/disabling the consumer POM feature.
     *

					updates <- cache.clone()
					return
				}
				cache.replace(v.Name, v.Parent, v.Entry)
				cache.Info.LastUpdate = time.Now()
			}
		}
	}()

	// Restrict parallelism for disk usage scanner
	// upto GOMAXPROCS if GOMAXPROCS is < len(disks)
	maxProcs := runtime.GOMAXPROCS(0)
	if maxProcs < len(disks) {
		disks = disks[:maxProcs]
	}

	// Start one scanner per disk

        performProjectActivation(context, request.getProjectActivation());
        performProfileActivation(context, request.getProfileActivation());

        //
        // Builder, concurrency and parallelism
        //
        // We preserve the existing methods for builder selection which is to look for various inputs in the threading

     */
    public Enumeration<?> propertyNames() {
        return Collections.enumeration(storage.keySet());
    }

    /**
     * Calls the map method put. Provided for parallelism with the getProperty method.
     * Enforces use of strings for property keys and values. The value returned is the result of the map call to put.
     *
     * @param key the key to be placed into this property list.

    BlockingQueue<Future<T>> futureQueue = Queues.newLinkedBlockingQueue();
    long timeoutNanos = unit.toNanos(timeout);

    // For efficiency, especially in executors with limited
    // parallelism, check to see if previously submitted tasks are
    // done before submitting more of them. This interleaving
    // plus the exception mechanics account for messiness of main
    // loop.

    try {

    ```xml
    <dependency>
      <groupId>com.squareup.okio</groupId>
      <artifactId>okio</artifactId>
      <version>1.3.0</version>
    </dependency>
    ```

 *  **Fix: improve parallelism of async requests.** OkHttp's Dispatcher had a
    misconfigured `ExecutorService` that limited the number of worker threads.
    If you're using `Call.enqueue()` this update should significantly improve
    request concurrency.

- API validation relaxed allowing Indexed Jobs to be scaled up/down by changing parallelism and completions in tandem, such that parallelism == completions. ([#115236](https://github.com/kubernetes/kubernetes/pull/115236), [@danielvegamyhre](https://github.com/danielvegamyhre)) [SIG Apps and Testing]

        if (localRepositoryPath != null) {
            request.setLocalRepositoryPath(localRepositoryPath);
        }

        //
        // Builder, concurrency and parallelism
        //
        // We preserve the existing methods for builder selection which is to look for various inputs in the threading