Intro paragraphs about SSL/TLS certificates and domain coverage

Author: RebeccaTamachiro

src/content/docs/dns/manage-dns-records/how-to/create-subdomain.mdx

@@ -16,6 +16,10 @@ For more guidance on redirecting a subdomain — either to your main domain or a
 
 ## SSL/TLS for subdomains
 
+While DNS is what communicates where your website or application can be reached, SSL/TLS is what enables websites and applications to establish connections in a secure way.
+
+If your subdomains are not correctly covered by an SSL/TLS certificate, your visitors will find a warning on their browser stating that your website or application is not secure.
+
 <Render file="ssltls-subdomains" product="dns" />
 
 ## Customize subdomain behavior

src/content/docs/dns/manage-dns-records/how-to/create-zone-apex.mdx

@@ -33,4 +33,8 @@ For more guidance, refer to [Redirect domain to subdomain](/fundamentals/setup/m
 
 ## Get free SSL certificates
 
+While DNS is what communicates where your website or application can be reached, SSL/TLS is what enables websites and applications to establish connections in a secure way.
+
+If your domain is not correctly covered by an SSL/TLS certificate, your visitors will find a warning on their browser stating that your website or application is not secure.
+
 Cloudflare offers free, unshared, publicy trusted [Universal SSL certificates](/ssl/edge-certificates/universal-ssl/) to all Cloudflare domains.

src/content/docs/ssl/edge-certificates/index.mdx

@@ -14,6 +14,8 @@ import { GlossaryTooltip } from "~/components"
 
 Consider the information below for guidance on how to choose different edge certificates for common use cases, or refer to the other pages in this section for more options.
 
+If you are not familiar with what SSL/TLS certificates are, refer to [Concepts](/ssl/concepts/).
+
 ## Use cases
 
 ### Simplify issuance and renewal