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:

### ¿Es la concurrencia mejor que el paralelismo? { #is-concurrency-better-than-parallelism }

¡No! Esa no es la moraleja de la historia.

La concurrencia es diferente del paralelismo. Y es mejor en escenarios **específicos** que implican mucha espera. Debido a eso, generalmente es mucho mejor que el paralelismo para el desarrollo de aplicaciones web. Pero no para todo.

### Concorrência é melhor que paralelismo? { #is-concurrency-better-than-parallelism }

Não! Essa não é a moral da história.

Concorrência é diferente de paralelismo. E é melhor em cenários **específicos** que envolvam um monte de espera. Por isso, geralmente é muito melhor do que paralelismo para desenvolvimento de aplicações web. Mas não para tudo.

### Конкурентность лучше параллелизма? { #is-concurrency-better-than-parallelism }

Нет! Мораль истории не в этом.

### Ist Nebenläufigkeit besser als Parallelität? { #is-concurrency-better-than-parallelism }

Nein! Das ist nicht die Moral der Geschichte.

* the `Authorization` header
* the forwarded header

* the dependency injection system
* the dependency
* the dependable
* the dependant

* I/O bound
* CPU bound
* concurrency
* parallelism
* multiprocessing

* the env var
* the environment variable
* the `PATH`
* the `PATH` variable

* the authentication
* the authentication provider
* the authorization

					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.

     */
    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.