Analog TV signals are transmitted over the air as frequency and amplitude modulation, the same as with radio. Digital TV is also transmitted over the air, but as bits and pieces of data, very much like computer files and streaming or a wireless Internet signal.
Function: Analog
Analog TV uses both types of radio frequencies, sending video over AM and audio over FM. The U.S. signal standard for analog TV is NTSC.
Effects
The quality of analog TV is greatly affected by airwave interference, along with the exact distance and location of any television picking up the signal.
Other Issues
The addition of color greatly affects analog TV signals, as it wasn't a factor when NTSC was adopted following Word War II. Many stations have different color shades because of this.
Benefits: Digital
The digital TV signal was designed to accommodate black-and-white and color video along with audio as either a progressive or interlaced signal. This allows signal flexibility.
Potential
Digital television also transmits the same analog signal in less bandwidth space, allowing more space for extra channels with features like extra languages and surround sound.
Tags: along with, transmitted over