The traditional model of education that takes place in a classroom, and which is still the most common today, was developed long before the diffusion of information and communication technologies.  Still, a much less common format (even after COVID) is centuries old and has recently been driven by such technologies: distance education. This is a format where you learn primarily from educational materials and resources rather than direct exchange with the teacher. This relationship became more complex from these technologies, allowing exchanges in real time and diversifying materials and interactive possibilities, giving rise to online education; also known as e-learning. An area linked not only to distance, but also to movement, mobile learning or m-learning (which could be translated as mobile education or mobile learning, but in Spanish it is common to use the term in English) is different from this format.
It's not about cell phones
It is true that m-learning is closely linked to mobile devices, but the center of this methodology is not the device that allows connection, but the possibility of ubiquitous learning that takes place during movement. In other words, m-learning is a part of e-learning, but while e-learning is characterized by connectivity, interactivity and multimedia content, m-learning is also light, fast, spontaneous and informal.  In this sense, some consider m-learning as a step “beyond” or a more advanced form of e-learning, bringing, if you like, education to people through devices that they manipulate on a daily basis . One of the reasons that could motivate this line of thinking is that the technologies associated with these devices, which currently allow and even promote this format, are advancing rapidly and are capable of responding to the wishes of the new generations. 
M-learning not only allows mobility, it is also wireless. In some way it arises as a reaction to traditional e-learning [which may sound paradigmatic], a platform to provide tools to a population that seeks knowledge anywhere and at any time.  For example, m-learning facilitates learning for workers while they face everyday problems, that of students when they do not know how to solve an exercise or that of anyone else looking for an answer to a question they do not know . This fact explains another of the fundamental characteristics of m-learning, informality.
Challenges and needs
Currently m-learning is intensely dominated by an informal setting.  When you want to develop formally through educational institutions - paradoxically - it is necessary to motivate students about the benefits of the format, at the same time that it is necessary to train teachers and create intuitive platforms that facilitate learning.  Other challenges of m-learning are the connection speed, the performance of the devices, the size of the screens, as well as the diversity of platforms and often the effort, investment of resources and human capital that it requires the adaptation of e-learning content to m-learning. 
To keep moving forward and aim for a medium structuring of your development without losing mobile and wireless potential, several conditions need to be considered. For example, m-learning has to maintain and develop its portability, personalize learning according to the skills, knowledge and needs of the stakeholders, while reaching most of the population and finding it useful and easy to use.  Although there are several points to take into account, it is important to underline that m-learning has to serve as a tool to reach more people. The devices and the connectivity on which their resources depend cannot demand medium or high-end standards that contribute to the inequality of the educational system as we know it.
Twenty years ago it was foreseen that the teaching process would become more flexible and would accompany the need for constant learning of the new generations, which would promote m-learning, powered by the new information and communication technologies.  With the passage of time, it has been possible to observe the consolidation of these visions and today it is easy to perceive that m-learning will continue to develop. The next generation will be much more ubiquitous, use more complex devices and devices, engage with intelligent systems, and have a strong presence in the virtual world.  Some experts even foresee that the devices will be able to understand the physiological state of people and with this information the systems will decide which activities to propose.  This would be a level of interaction that we have not seen so far, but that is related to the profiles that companies build from people's habits and allow them to display customized advertising.
M-learning is developed from e-learning as an agile and wireless option that allows ubiquitous learning. Its nature so far is fundamentally informal, but it has enormous potential that could take the formal education system to another level, more closely linked to today's hyperconnectivity.
 A. T. Korucu and A. Alkan, “Differences between m-learning (mobile learning) and e-learning, basic terminology and usage of m-learning in education,” Procedia - Soc. Behav. Sci., vol. 15, pp. 1925–1930, 2011.