Automated test generation is a mature area that has seen a lot of research, resulting in many test automation methods and tools for test creation. Nevertheless, practitioners often struggle to adopt them due to cognitive differences, terminology discrepancies, and, most importantly, the lack of a conceptual model to select suitable approaches for their specific context. We propose a taxonomy that characterizes the methods for automated test generation. The taxonomy can support researchers in identifying topics and opportunities for investigation and software practitioners in comparing and evaluating automated test generation methods. The taxonomy was constructed using a systematic process that involved analyzing secondary studies on automated test generation and existing taxonomies in the scientific literature. Direct observations and iterative refinements were included, followed by validation through conceptual evaluation and practitioner feedback. The resulting dimensions characterize automated test generation and its use in software testing. The taxonomy is organized into several dimensions: software artifact (i.e., type, notation, interfaces), test generation (i.e., objectives, methods, and monitoring), test execution, and test oracle. We demonstrate the taxonomy’s use by applying it to several automated test-generation tools. This paper provides the necessary concepts and a generic process for categorizing and assessing automated test generation approaches.