Dynamic means that this is something that is capable of change because it will be able to adapt easily depending on the settings that you would need it to be. Static is the opposite of dynamic. This is known to be more fixed. When you sign up to the internet, you will either be connected to a dynamic or a static connection.
A lot of users will prefer to use dynamic connections as compared to static ones probably because they would need different IP addresses depending on what they are trying to access. Those who are hosting servers will need static addresses though in order to make the process more simple.