I tried doing a quick search on this question and was very surprised that this information feels very obscure as if it is almost never discussed. Complex frequencies appear in many mathematical concepts such as Laplace Transforms and sources mention the rectangular form as $ s = σ + jω $, but fail to actually explain what the rectangular components stand for.
I saw one source mention this.
the real part(sigma) is called nepper frequency it control amplitude of function and its unit is nepper/second . and imaginary part(omega) is called oscillation (radian) frequency it control oscillation and its unit is radian/second.
I just decided to ask here to know what those actually mean. Also, if some people might respond with the rectangular components being irrelevant or having little significant application I just really want to ask this for the sake of knowing.
EDIT: I am asking what σ and ω in $ s = σ + jω $ stand for and why those quantities represent the real and imaginary components of the complex frequency. The source which I cited said that σ is nepper frequency and ω is oscillation frequency.