A Content ID claim is YouTube's notification that you might be using copyright-protected content. Like a copyright takedown, it could be disputed and retracted but will not result in a strike. However, the copyright claimant might utilize your video for monetization, collecting viewers' data, or the claimant may choose to block it from certain countries.
A copyright takedown is a legal procedure that a copyright owner initiates. This will result in a copyright strike (could be disputed and retracted). Three consecutive strikes within 90 days will result in the termination of your account/channel.
More information could be found on YouTube's Help page.