Graphs in pattern recognition have been studied since the late seventies with alternating events of successes and failures. Far from wanting to propose a unique survey on the subject, we aim to present the areas in which graphs have been shown to be effective and to illustrate the problems still open in this research domain, with a focus on recent developments moving in the direction of deep learning. This work intends to arouse the interest of neophytes to this interesting domain that is the representation of the world through graphs.