What is Master Repository

Master repository stores the information defined by topology manager and security navigator.
 Master Repository stores the following information

1. Security Information: users, profiles, access privileges
 2. Topology information including technologies, Data servers, physical and logical schemas , contexts, agents and languages
 3. ODI versions and objects 

What is Work Repository

Each work repository is attached to a master repository, therefore, information about the physical connection to a work repository is stored in the master repository it is attached to.
Defining a connection to a work repository consists of defining a connection to a master repository, then selecting one of the work repositories attached to this master repository

Work repository should always attached to a master repository.

Work repository stores the information defined in Designer navigator .

It stores the following information:

1. Data models: metadata, constraints, references, data lineage, etc

2. Projects: interfaces, packages, procedures, folders, knowledge modules, etc

3. Scenarios, scheduling information and logs

Work repository contents manged by designer and operator.