TXT records are a type of Domain Name System (DNS) record that contains text information for sources outside of your domain. You add these records to your domain settings. You can use TXT records for various purposes. TXT records are normally used for email spam prevention and domain ownership verification.
v=spf1 include:spf.protection.outlook.com -all
MX records are mail exchange records and are used for sending email to your email address. The MX records tell which mail server will receive the incoming emails for that specific domain and where those emails should go.
A records are the most basic type of DNS record and are used to point a domain or subdomain to an IP address.