In the cerebellum!
stored in the Hippocampus.
Learning occurs in the cerebrum of the brain. Through a network of neurons, sensory information is transmitted by synapses along the neural pathway and stored temporarily in short-term memory, then neural pathways carry these memories to the structural core, where they are stored in long-term memories.
long-term potentiation.
B.======================================================Allow me to add:each species and culture shares ancient memories, stored in the unconcious part of the mind.
Long term and short term memories are stored in different sections of the brain. Damage to one section by trauma or disease does not necessarily affect the other parts. The writer knows of a woman who had surgery for a cerebral aneurysm some years ago. She now has practically no short-term memory. She can recall things that happened years ago, but five minutes later she will not remember talking about it. However, if we talk about something long enough it will get into long-term and she will then be able to remember it. Needless to say, this is a really debilitating condition.
some kind of associative memories
Hippocampus
no.memories are stored in your temporal lobes.
Memory is stored in the brain. Some things like an odd answer to a question in maths are stored in short term memory and others like your birthday are stored in long term memory.
Long-term potentation
Typically, memories are stored in Dumbledore's pensieve (when not in their original owner's heads). But specifically in Deathly Hallows, Snape's memories are stored (temporarily) in a vial that Hermione conjured. They are later dumped into the aforementioned pensieve.
short-term memory-apex long-term potentiation.