Comprehensible input refers to language input that learners can understand, with the appropriate level of challenge. It is a key concept in language acquisition, as it suggests that learners need to be exposed to language that is slightly above their current level in order to facilitate learning. This input should be comprehensible, meaning that learners are able to understand the main message or meaning, even if they don't understand every single word or structure used. Comprehensible input is often provided through meaningful and context-rich communication, such as conversations, stories, or authentic texts.
