Synchronous and asynchronous communication are two fundamental modes of data transmission in computer networks.

Synchronous communication: involves the real-time exchange of data between sender and receiver, requiring both to be active simultaneously. It relies on a shared clock signal to coordinate data transfer, ensuring precise timing. This mode is suitable for tasks that demand immediate responses and constant interaction. Examples include video conferencing, live streaming, and VoIP (Voice over Internet Protocol) calls, where both parties are engaged simultaneously, and data packets are exchanged in real-time to maintain a seamless interaction.

Asynchronous communication, on the other hand, allows data to be sent and received at different times, without requiring both parties to be active simultaneously. It uses start and stop bits to signal the beginning and end of data packets, enabling the receiver to handle data at its own pace. This mode is ideal for tasks that do not require immediate responses. Examples include email, messaging apps (like WhatsApp or SMS), and online forums. In these cases, a sender can transmit a message, and the recipient can read and respond at their convenience, allowing for flexibility in communication.

In summary, synchronous communication demands real-time interaction, while asynchronous communication offers flexibility by allowing delayed responses.