AWS Certificate Manager (ACM) is where AWS stores your SSL certificates. These certificates can be used with AWS resources that require SSL, such as ELBs or CloudFront distributions. You can also request SSL certificates through ACM; Amazon issued certificates are auto-renewed, so you don’t have to worry about them expiring.
However, sometimes you want to use a certificate from another issuer. In these cases, you can import your certificate directly into ACM and reference them from your SSL enabled resources. Unfortunately, imported certificates require manual renewal. Blue Matador monitors these certificates and will notify you when the time comes to renew them, so you never end up with an expired certificate! After you renew that certificate, you’ll need to re-import it into ACM.