Frequency Transform is used to study a signal's frequency domain characteristics. When using FFT to study the frequency domain characteristics of a signal, there are two limits : 1) The detectability of a small signal in the presence of a larger one ; 2) frequency resolution - which distinguishes two different frequencies.
In practice, the measured signals are limited in time and the FFT calculates the frequency transform over a certain number of discreet frequencies called bins.
This article analyzes the effect of having limited measurement interval and its consequence of "Spectral Leakage" phenomenon.
Matlab Codes are also given at the end of the article to simulate the illustrations