Cognitive load refers to the amount of mental effort required to process new information in working memory, which is limited in both capacity and duration.
In learning design, managing cognitive load means balancing intrinsic load (the complexity of the content itself) with minimizing extraneous load (unnecessary distractions like cluttered visuals, confusing interfaces, or overwhelming multimedia) so that learners can focus on meaningful knowledge transfer.
Resource: The learner-focused 6-step cognitive load checklist.