Personalization is a feature that occurs separately within each system that supports some kind of users’ interactions with the system. Generally speaking term “Personalization” means the process of deciding what the highest value of an individual is if (s)he has a set of possible choices. These choices can range from a customized home page “look and feel” to product recommendations or from banner advertisements to news content. In this monograph we are interested in personalization in educational settings. The topic of personalization is strictly related to the shift from a teacher-centred perspective of teaching to a learner-centred, competency-oriented one. Two main approaches to the personalization can be distinguished: user-profile based personalization and rules-based personalization. In the first case this is the process of making decisions based upon stored user profile information or predefined group membership. In the second case this is the process of making decisions based on pre-defined business rules as they apply to a segmentation of users. This chapter presents the most popular adaptation forms of educational materials to learners.