Which communication forms are synchronous?

1. Which communication forms are synchronous?
2. Which ones are asynchronous?
3. What type of information would be conveyed by each form?
4. What is needed in hardware and software for each?

There are many communications on the internet. Such as Skype, Messenger, Chat room and internet(blogging, sending mail, postcard). They are all synchronous but some times they all can get asynchronous if a virus  comes or something goes wrong with the hard drive.. They all could get the same information conveyed but I think the fastest on might be Skype because you can talk directly instead of wasting a little time typing. If you can't speak in the mic then you should type. For the internet to work you need an internet connection. For Skype to work you should download it from its home site.For the Messenger to work make an account on that messenger.