A lot of users get confused with the difference between a glossary, data dictionary and catalog and often end up mixing them up. Here is a quick easy definitions with an example illustration for easy comprehension.
Business Glossary
A collection of business terms with their definitions and other useful related information. The business glossary is agnostic of any data bases or tools.`
Data Dictionary
A repository of information about data that provides the descriptions of the data elements and its meta data (Data type, Size, allowed values, default values, relation to other elements, descriptions, keys). It is data base specific, list of tables and fields. Provides an application view of the data.
Data Catalog
An enterprise-wide asset providing a single reference source for the location of any data set required for varying needs. It is a directory of data sets, data lakes, data warehouse and any data store. Inventory of data sets and list of data dictionaries. The data catalog connects the business glossary to the data dictionary