collinsc wrote
Can anyone explain what asynchronous is? iis it dependent on another program/job running? |
First the let's give the dictionary definitions (from Merriam-Webster) of both synchronous (since it's the opposite of asynch) and asynchronous:
Definition of SYNCHRONOUS
1: happening, existing, or arising at precisely the same time
2: recurring or operating at exactly the same periods
Definition of ASYNCHRONOUS
1: not synchronous
2: of, used in, or being digital communication (as between computers) in which there is no timing requirement for transmission and in which the start of each character is individually signaled by the transmitting device
And to answer your second question, if the term asynchronous is used then it means the "thing" you're referring to is NOT dependent on another program or job.
In IT and application development, the two terms are used in many different types of situations and it may have slightly different meanings.
For examples, if you refer to two activities, they are considered synchronous if they occur at the same time and asynchronous if they don't have to occur at the same time.
Here's another example: if an application is calling an external service (let's say a web service) the call may be referred to as synchronous if the application waits for a response from the service before continuing its processing. On the other hand, if the application does not wait for the response (it may check it later) then the call is considered to be asynchronous.
Hope this helps!
Do you have a specific example in mind that you had in question?
Adrian