https://www.pcworld.idg.com.au/article/386100/what_difference_between_an_intel_core_i3_i5_i7_/
The Core-i3 is a lower cost version of the popular Intel chip series, it has fewer processors but is perfect for just surfing the web, writing Microsoft Office documents and checking email, Facebook, Youtube videos, etc.
For serious business use with multiple applications or higher end photoshop, CAD and graphics software, you'll want to look at the Core-i5 or Core-i7 processors.
