Blends are two consonants that come together and they both keep their sounds. Some examples of blends are cr in crab, st in star, and nd in find.
Digraphs are two consonants that come together to make one sound. Some examples of blends are ch in chat, th in bath, and ph in phone.
Blends and Digraphs: How to Teach Them (web article)
Digraph/CVC nonsense words on online flashcards (sign up is free)
Blends nonsense words on online flashcards (sign up is free)
Blends & digraphs nonsense words on online flashcards (sign up is free)
Online blends game
Various online digraph games on education.com
Online digraphs game
Printable digraph board games
Printable digraph activities