This paper introduces the concept of the ubiquitous class, a teaching approach that transcends the time and space constraints of the traditional classroom. In the context of Education 4.0, characterized by the digital transformation of teaching and learning processes, we examine the challenges and opportunities of implementing this approach. Our primary aim is to classify teaching methods based on their temporal and spatial dimensions and to explore how these classifications relate to the use of ubiquitous teaching. We propose that ubiquitous teaching is the optimal method for achieving the anytime/anywhere and personalized learning experience that Education 4.0 demands. We further explore how this classification can serve as a foundation for the digitalization of the classroom, leading to the creation of a Digital Twin of the learning process. By applying this concept to the learning process, we aim to create a more effective and efficient educational system that adapts to the needs and preferences of each learner. We delve into current technological trends such as the Digital Twin, Artificial Intelligence, and Virtual Reality, and explore how they can support the ubiquitous class. We present real examples of how these technologies can create immersive and interactive learning environments that transcend the physical boundaries of the classroom. Finally, we analyze the advantages and disadvantages of the ubiquitous class compared to the traditional class, as well as the implications for teachers, students, and educational institutions. We conclude that the ubiquitous class concept is not only relevant but also a key element in understanding and fostering the digital transformation of education, thereby facilitating the implementation of Education 4.0.