The physical layer of the OSI Model includes protocols that look after:

The physical layer of the OSI Model is fundamental in networking as it deals with the actual transmission of raw data bits over a physical medium. This layer includes critical functions such as defining the electrical and physical specifications of the data connection, representing signals in terms of voltage levels, timing of the signals, and transmission rates.

Signal levels are vital because they determine how bits are represented physically on a medium, whether it's copper wire, fiber optics, or wireless signals. This involves setting standards for the physical characteristics of the transmission medium and the electrical signals that travel across it.

In understanding the full scope of the physical layer, it's important to note that framing and media access control, while essential for data transmission, belong to higher layers of the OSI Model. Framing is typically associated with the data link layer, where data packets are packaged for transport, and media access control involves controlling how data packets are placed on and retrieved from the network medium, which also falls under the data link layer responsibilities.

Thus, focusing solely on signal levels accurately reflects the direct responsibilities of the physical layer in managing the physical aspects of data transmission. Therefore, while elements like framing and media access control are important components in the overall network architecture, they do not pertain directly to the physical