Difference between a Gallery and an Album?

[Gimpymoo]

Started to use the Blog for the first time and thought it would be cool to dump all required pictures in a gallery then just add that gallery to the blog post.

You are only allowed to select albums to import from, but what is the difference?

Is an Album a sub-category of a Gallery?

Maybe I am thinking of it wrong, but I would find it easier to put everything into a single gallery, then when creating a blog just select from the gallery which pictures I wish to add to the blog post, if that makes sense? Having to categorise is fine if your starting from new but if you already have a load of content to transfer across, it is a bit of a pain,

Thanks.