The Shards

Digital Shards are a small crystal like object which appear when a Digimon first finds its human partner. The shard represents one of the nine crests (Courage, Sincerity, Light, Knowledge, Friendship, Hope, Reliability, Kindness, Love) and is the same color as the corresponding crest. 
The shard allows any one digital object to become a Digivice for the human when touched, and then gives their Digimon the ability to Digivolve. Over time the shards can be collected and with each addition, allows for the Digimon to evolve to a higher level.