This lecture will present the basic concepts of the blind signal separation (BSS) problem and its solutions, especially solutions that employ independent component analysis (ICA). The presentation is formulated to be an introduction. Therefore, the paper explains the underlying arduous mathematical concepts with a minimalist reliance on pre-existing mathematical know-how of the audience. Topics to be covered include the BSS problem statement, an intuitive explanation of how ICA techniques are applied, how and why they work, and application domains of the presented methods.