% (Wildcard - Character(s) to Match) (Transact-SQL)
Matches any string of zero or more characters. This wildcard character can be used as either a prefix or a suffix. For more information, see Pattern Matching in Search Conditions.
Examples
The following example returns all the first names of people in the Person table of AdventureWorks2008R2 that start with Dan.
USE AdventureWorks2008R2;
GO
SELECT FirstName, LastName
FROM Person.Person
WHERE FirstName LIKE 'Dan%';
GO