The concept of 'cognitive load' refers to the total amount of mental effort being used in the working memory. In educational settings, instructional design aims to manage this load to optimize learning. According to cognitive load theory, learning is hindered when the intrinsic complexity of the material, combined with the way it is presented, exceeds the learner's available working memory capacity. Extraneous cognitive load, which is generated by poor instructional formats, can be reduced by careful design, freeing resources for the essential processing of information. However, recent studies suggest that some level of desirable difficulty, such as interleaving different topics, can enhance long-term retention despite increasing initial cognitive effort. This paradox indicates that the relationship between cognitive load and learning outcomes is not linear, and that optimal learning may require a balance between reducing unnecessary load and introducing productive challenges.