Q:

SSIS look up vs fuzzy lookup

In SQL Server Integration Services, there are two types of look ups:

Normal look ups
Fuzzy look ups

What is the difference between them?

A:

There are good descriptions of all of SSIS transformations on MSDN.  
Lookup transformations perform lookups by joining data in input columns with columns in a reference dataset. You use the lookup to access additional information in a related table that is based on values in common columns. 
As an example, if you are populating a fact table, you might need to use a lookup to get the surrogate key from a dimension table by joining based upon the business key.
Fuzzy Lookup transformations perform data cleaning tasks such as standardizing data, correcting data, and providing missing values. The Fuzzy Lookup transformation differs from the Lookup transformation in its use of fuzzy matching. The Lookup transformation uses an equi-join to locate matching records in the reference table. It returns records with at least one matching record, and returns records with no matching records. In contrast, the Fuzzy Lookup transformation uses fuzzy matching to return one or more close matches in the reference table.  
Fuzzy lookups are commonly used to standardize addresses and names.

