Host

host is about the simplest DNS query tool there is. But sometimes, that's all you need. Here, let's use it to convert from a domain name to an IP address:

These 3 queries should illustrate how forward lookups work.

Reverse lookups? Easy like pie: See how easy that is? Bulletproof.

About the only option you might wanna see is:

The -t switch allows you to specify the type of record to lookup. See the dig page for more record types.

Additional info
Use the manpage: