TXT records are generally used for informative purposes. They can store any type of free text information about a particular hostname (domain name) including the name of the hosting provider, contact details (contact person, phone number, email address, etc.) and other related details.
TXT records are most commonly used for storing SPF (Sender Policy Framework) records, thus helping for an SPF Protection to be performed for a certain domain name. SPF records contain information that will help block any attempts of people who try to send fake spam messages that appear to be sent from your email address.
Example TXT Record:
example.com IN 86400 TXT "Hostname used for examples only"