What is the difference between fampridine and dalfampridine?

Could you please clarify the key distinctions between fampridine and dalfampridine? I'm curious to understand how these two compounds differ in terms of their chemical structures, intended uses, potential side effects, and any other relevant factors that might differentiate them. Is there a specific medical condition or scenario where one might be preferred over the other? I'm looking forward to hearing your insights on this topic.