Synchronous Communication refers to all sorts of conversations in which both (or more) parties exchange information in real-time. Tools like Zoom, Google Meet, etc. are some examples of tools that help teams carry out Synchronous conversations.
Synchronous communication is used for regular meetings with team members to discuss the goals and performance of the team. Watercooler chat (casual interaction between the team members) also takes place over synchronous communication channels.
Generally, synchronous communication is used when you want quick feedback from the other party or want everyone to be on the same page as you are.
Asynchronous communication is just the opposite of synchronous communication. Information is exchanged between two parties over a period of time in an asynchronous form of communication. Common tools used for asynchronous communication are emails, Slack, etc.
The basic idea behind using this mode of communication is that the other person might be busy with some ongoing work and involving him in a conversation at that right moment might hamper his productivity and overall satisfaction that he derives from working with the team.
With an asynchronous mode of communication, teammates have the comfort of responding to the message at a time they feel convenient and not give up the task they are working on for the same. Having said that asynchronous is not really a good option if you need instant feedback.
Creating long stretches of focus - Provided the option of replying to a message in their own time, team members can focus on their work and hence be more productive.
Better in adapting to different time zones - If your team is distributed among different time zones then going async will make sure that all the members have a proper work-life balance.
In-depth interaction- A real-time conversation with your team members is necessary if you are brainstorming ideas for a campaign or discussing the goals for the quarter or explaining an idea to bring everybody on the same page. The same could not be accomplished over asynchronous channels.
There is extensive research done on which medium of communication is best in which situation. Media Research Theory is a result of one of those research and was introduced by Richard L. Daft and Robert H. Lengel way back in 1986. MRT tries to define the ability of a communication channel to successfully transmit different types of information and the different factors upon which its success depends.
According to MRT, communication channels are ranked from top to bottom (rich mediums to lean mediums). A rich medium is used in case of getting quick feedback, establishing personal focus, and reducing the equivocality (a cool word for ambiguity) of the information being exchanged.
Synchronous communication falls under rich medium as it qualifies all the criteria mentioned above. You should be using this mode of communication if you need instant feedback or feel that the information can be ambiguous to the receiver unless they are explained the same.
On the other hand, the asynchronous form of communication(lean medium) is used when instant feedback is not required and the information is unambiguous.
Businesses should start by understanding the importance of a proper communication system for its overall functioning. Synchronous/asynchronous channels of communication alone cannot satisfy the needs of a remote team as both of them are suited for different needs and situations. A good communication structure will enable teams to be more productive and be more close to each other at the same time.