Most data transmission processes that are done through communication channels are facilitated in the form of the Open Systems Interconnection (OSI) model protocol layers. The OSI model lays out the major layers and topics in an intersystem communication process.

The following diagram shows the general structure of an OSI model:

As indicated in the preceding diagram, there are seven main layers of communication in a data transmission process, with varying degrees of computing level. We will not be going into the details of the purposes and specific functions of each layer, but it is still important that you understand the general ideas behind the media and host layers.

The three bottom layers contain fairly low-level operations that interact with the underlying process of the communication channel. The operations in the physical and data link layers include coding schemes, access schemes, low-level error detection and correction, bit synchronization, and so on. These operations are used to implement and specify the logic of processing and preparing data before transferring it. The network layer, on the other hand, handles forwarding packets of data from one system (for example, the server) to another (for example, the client) in a computer network, via determining the address of the recipient and which path of data transfer to take.

On the other hand, the top layers deal with high-level data communication and manipulation. Among these layers, we will be focusing on the transport layer, as it is directly utilized by the asyncio module in implementing communication channels. This layer is often viewed as the conceptual transition between the media layers and the host layers (for example, the client and the server), responsible for sending data along end-to-end connections between different systems. Additionally, because packets of data (prepared by the network layer) might be lost or corrupted during transmission processes due to network errors, the transport layer is also in charge of detecting these errors via methods in error detection code.

The other host layers implement mechanisms for handling, interpreting, and providing the data sent from another system. After receiving data from the transport layer, the session layer handles the authentication, authorization, and session restoration processes. The presentation layer then translates the same data and reorganizes it into an interpretable representation. Finally, the application layer displays that data in user-friendly formats.