A report on Physical layer, Point-to-point (telecommunications) and Computer network

In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer; The layer most closely associated with the physical connection between devices.

The term is also used in computer networking and computer architecture to refer to a wire or other connection that links only two computers or circuits, as opposed to other network topologies such as buses or crossbar switches which can connect many communications devices.

From the OSI model's layer perspective, both switches and repeater hubs provide point-to-point connections on the physical layer.

Other topics associated with the physical layer include: bit rate; point-to-point, multipoint or point-to-multipoint line configuration; physical network topology, for example bus, ring, mesh or star network; serial or parallel communication; simplex, half duplex or full duplex transmission mode; and autonegotiation

Bus network: all nodes are connected to a common medium along this medium. This was the layout used in the original Ethernet, called 10BASE5 and 10BASE2. This is still a common topology on the data link layer, although modern physical layer variants use point-to-point links instead, forming a star or a tree.