There is no difference at all.

Generally, they mean exactly the same thing, but 'have got' is more informal. In questions, using 'have' is typically more formal than 'have got', but that depends on the area the speaker comes from. In parts of Ireland, for example, it's common to say 'Have you a pen?', but I would personally always say 'Have you got a pen?'. In the area of England where I come from saying 'Have you a pen?' is more formal and old-fashioned. However, there's not a huge difference between saying 'I have a pen' and 'I have got a pen'.

my teacher has told me once that using have is more academic than using have got. there is no difference in meaning i guess.

Has got and have got are informal and mainly used for emphasis. More often than not, these are contracted, such as, She's got or they've got.

have got means lost.forgot but have means get