I came across the article by Hervé Abdi about generalized SVD. The author mentioned:
The generalized SVD (GSVD) decomposes a rectangular matrix and takes into account constraints imposed on the rows and the columns of the matrix. The GSVD gives a weighted generalized least square estimate of a given matrix by a lower rank matrix and therefore, with an adequate choice of the constraints, the GSVD implements all linear multivariate techniques (e.g., canonical correlation, linear discriminant analysis, correspondence analysis, PLS-regression).
I'm wondering how the GSVD is related to all linear multivariate techniques (e.g., canonical correlation, linear discriminant analysis, correspondence analysis, PLS-regression).