Question on the 2 isomers of butene (C4H8)?

i understand that butene has the isomers but-1-ene and but-2-ene, where the position of the double bond is between carbon atoms 1 and 2 and then between atoms 3 and 4 (respectively). i'm just confused, do their properties at all differ? or is it just the position of the double bond which makes them look different? and where is the position of the double bond in the normal butene alkene? as one book says its 1-2 and my other book says 3-4. Thanks.