What is the difference between semantic and episodic memory?

The long term memory is arguably divided into three separate stores, these include the semantic memory, the episodic memory and the procedural memory. Tulving argued that these stores are distinct and seperate, working in isolation from one another. This means that one could damage the right prefrontal cortex (the location of the episodic memory) resulting in the loss of day to day memories, however still have a fully functioning semantic and procedural memory. 

The main distinctions between the stores are due to the prime functions of the stores. The episodic memory is necessary in order to remember events that have happened (think of this as your mental diary). This store also combines memories of people, places and behaviours and objects. You can also remember the time of these events, for example you can remember the last time you went to the dentist, saw your grandma or brushed your hair. The semantic memory on the other hand is akin to your mental dictionary and thesaurus. For example, this area of your memory would store general knowledge and information, such as your times tables, what colour the sky is and what the word "clever" means when your teacher writes this in your book. These memories are not time stamped, for example you cannot remember when you learnt 3X3=9, you just "know it".