Forward DNS Lookup:Takes a domain name, like example.com, and returns an IP address, such as 192.0.34.166.
Reverse DNS Lookup:Takes an IP address, like 192.0.34.166, and returns a domain name, such as example.com.
MX Record Lookup:Takes a domain name, and returns the IP address responsible for that domain's email.
DNS Record Lookup:Takes a domain name, and returns all the DNS records associated with it.