- modular form: (1) modularity, (2) holomorphic, (3) holomorphic at cusps. How they are generalized or restricted ? - cusp form: (3) vanishes at cusps. - non-holomoprhic modular form(?): (2) real analytic, and eigenfunction of Casimir operator. - weakly holomorphic modular form: (3) allowing finite-order pole at cusps. - harmonic Maass form: (2) real analytic, and annihilated by weight-$k$-Laplacian. (3) at most linear exponential growth at cusps. - weak Maass form: (2) real analytic, and eigenfunction of weight-$k$-Laplacian. (3) at most linear exponential growth at cusps. - mock modular form: ``holomorphic part'' of harmonic Maass form. - meromorphic modular form: - weakly holomorphic cusp form: weakly holomorphic, and its Fourier expansion has no $q^0$ terms. (still may allow $q^n$ with negative $n$.) - quasi-modular form Generalization to another direction - modular form with half integral weight - Siegel modular form - Jacobi form Notations - $M_k$ modular form - $S_k$ cusp form - $M^!_k$ weakly holomorphic modular form - $S^!_k$ weakly holomorphic cusp form - $QM_k$ quasi-modular form