Difference between digital and analog?

[weaksauce]

Well for example with computer screens or tv's, what's the difference between a screen that uses dvi/hdmi and one that uses vga/component?

 

[3dilettante]

Well for example with computer screens or tv's, what's the difference between a screen that uses dvi/hdmi and one that uses vga/component?

It's in the manner that data is represented in transmission. With analog transmission, a signal's strength/voltage/frequency/and-so-on is used to represent any number of values. Digital devices still use the same means of communication, but they restrict the way that a given value can be represented.

A signal is supposed to be in one of two(usually) states. It's popular to use on/off or 1/0, but it's more of a way of explaining the idea.

Whatever value the data is supposed to have is represented by a string of digital states, as opposed to far fewer analog states. A digital signal will take more bits to transmit than an analog one, but analog has a lot of problems with interference and ambiguous state.

A binary digital system only has one possible area of ambiguity, where something is in between 1 and 0. Analog systems can have any number of gray areas that make things complicated.

 

[soylent]

In general digital stuff is noise-less but more prone to catastrophic failure. Hell change one bit in a file and you might make it unusable(especially if it's in the header. Your 640x480 screenshot may be interpreted as a 33408x480 screenshot with a mismatching data chunk size, if the image displays it will be clearly mangled. Or the colour depth may be interpreted as 280 BPP instead of 24). As long as digital stuff works, it really does WORK, analog is always slightly degraded.

When it comes to displays the digital signal is converted to analog much later than a signal converted to analog at the graphics card. There are fewer occassions for noise, interference and crosstalk to have an effect on the signal.

 

[_xxx_]

Analog means that the signal is continuous, the values corresponding with the voltage mostly. A digital signal is a stream of numerical velues being transferred at a certain sample rate (the real value is being periodically sampled and represented as a number, not continous).