A lot: The Samsung Galaxy Ace is an older midlevel phone that offers you the advantages of an Android smartphone, with decent technology, without a hefty price tag. You'll have the basic features of all smartphones (Internet, applications, games, wifi, bluetooth, multimedia, etc.) but it won't be top of the line.
The Galaxy Note is one of the top of the line phones and brings (besides a huge screen and a hefty price tage) media production functions with it live film and picture editing. Its a great device but expensive and most people don't need the media functionality. But in a professional context it's a great phone if you know your way around the system.
what is the differenced between a Samsung galaxy ace and a Samsung galaxy note
there are vast differences starting from the design (hadrware build) to the programing of the software. the appearance is the first difference that you will witness it has 5.3 inches of screen size along with better resolution and pixel count as well. The presentation of the software is also boasted up in Galaxy Note with Andorid 4.1 Jelly Bean, on the contrary Galaxy ace still has the Gingerbread in-built in it.
Moreover, the Note has (8mp and 2mp) rear and front facing camera where as Galaxy Ace has only 5 Mp of primary camera without the secondary snapper in it.