What is Layer 1 (Layer 1 (Physical Layer))?

The physical layer is the first and lowest layer in the seven-layer OSI model of computer networking. The physical layer characterizes communicating a stream of bits over a physical data link connecting network nodes. The bitstream might be assembled into code words and changed over to a physical signal that is communicated over a transmission medium. The physical layer comprises the electronic circuit transmission technologies of a network. The physical layer performs bit-by-bit or symbol-by-symbol data information to convey a physical transmission medium.