We saw how to create SSL/TLS certificates using ACM. We can also import certificates created outside of AWS. We can use these certificates with services such as AWS Load Balancer, API Gateway API, and a CloudFront distribution. 

Apart from using SSL certificates and HTTPS, we can also add additional security to our web applications using services such as AWS WAF, AWS Shield, AWS Shield Advanced, and AWS Firewall Manager. 

You may also explore Let's Encrypt for creating free SSL/TLS certificates for your AWS deployments. Let's Encrypt is a certificate authority that provides free SSL certificates.