Declarative memory is the aspect of memory that stores facts and figures. It applies to standard textbook learning. It is based on pairing the stimulus and the correct response. For example, the question "What is the capital of Sierra Leone?" and the answer "Freetown". The name declarative comes from the fact that we can explicitly "ask" our brain to make a connection between a pair of simuli. Declarative memory is subject to forgetting and requires repetition to last for years. Declarative memories are best established by using active recall combined with mnemonic techniques and spaced repetition.
Declarative memory can be divided into episodic memory, about things you have personally experienced (e.g. what you had for breakfast), and semantic memory, about general knowledge of the world (e.g. what is the capital of Canada).
Contrast with procedural memory.