Dealing with conflicts

This video is an additional video that you can watch if you wish to understand how the network resolves the issue of conflicting blocks. It happens every now and again that two valid blocks are produced at close to exactly the same time and that some nodes on the network receive them in a different order than other nodes. Then what? This video is rather technical but dives into how the protocol of the Bitcoin network resolves this issue.

Creator	Time	URL
Andreas Antonopoulos	11min	Full source

Takeaway The longest chain of valid blocks (the one with the most proof of work) is considered the true one. If two valid blocks are propagated across the network at the same time and there is temporary disagreement among nodes, the disagreement automatically gets resolved by miners voting with their computing power on which chain to work. Because this disagreement happens every now and again at the very edge of the blockchain (last blocks), Bitcoin transactions are considered fully confirmed after 6 blocks, although fewer confirmations are generally okay.