What is the difference between 'por' and 'para'?

First of all this is a great question and one that many people ask.We use 'por' when we want to talk about things such as mode of travel, duration and motivation (explaining why you did something). When using words such as 'through, for and by' in English we use 'por' for example 'I travelled by taxi'.We use 'para' when we want to talk about things such as destinations, recipients and goals. 'Para' often translates to English phrases such as 'in order to' for example 'I studied In order to pass the exam'.