Difference between UART and USAR

UART	USART
UART requires only data signal	In USART, Synchronous mode requires both data and a clock.
In UART, the data does not have to be transmitted at a fixed rate.	In USART’s synchronous mode, the data is transmitted at a fixed rate.
In UART, data is normally transmitted one byte at a time.	In USART, Synchronous data is normally transmitted in the form of blocks
In UART, data transfer speed is set around specific values like 4800, 9600, 38400 bps ,etc.	Synchronous mode allows for a higher DTR (data transfer rate) than asynchronous mode does, if all other factors are held constant.
UART speed is limited around 115200 bps	USART is faster than 115kb
Full duplex	Half duplex