What is Function of physical layer?

Describe me about the function of physical layer (synchronization of Bits).

Synchronization means that the transmitter and receiver should have an agreement on the nature as well as timing of the signals. The receiver must be able to determine, when to expect a new transmission and when to send acknowledgements. In data communication, data is transmitted in digital form bits (0, 1), so, Synchronization of bits means that the sender and the receiver should be synchronized at the same bit rate for accurate and successful transmission of data. It is done by Physical Layer.


For further detail, you are recommended to watch lecture 3 and visit the following link:
http://simple.wikipedia.org/wiki/Bit_synchronization