Time ---- frequency domain:: (please correct me if i have this idea wrong). When describing a quantity (say voltage (V) ) in the time domain we can write the value in terms of a certain position (usually fixed) and a certain time, This value corresponds to describing a complicated object (a wave) in a simple space. In the FREQUENCY domain we describe the value for V in the opposite sense ( a simple object a vector in a complicated space). My question here is why is it called only frequency domain when it corresponds to three coordinates ?

Question

Time ----> frequency domain:: (please correct me if i have this idea wrong). 

When describing a quantity (say voltage (V) ) in the time domain we can write the value in terms of a certain position (usually fixed) and a certain time, This value corresponds to describing a complicated object (a wave) in a simple space.

In the FREQUENCY domain we describe the value for V in the opposite sense ( a simple object a vector in a complicated space). My question here is why is it called only frequency domain when   it corresponds to three coordinates <freq, phase, magnitude > ?