VTiger 7 standard relationships between different modules are shown in this article Relationships connect different modules and the working of the modules depends on the quality and quantity of these relationships. Like other CRM systems, VTiger also use different relations to connect the modules. Standard VTiger most commonly use three types of relationships which are as following One to One (1:1) : One record of a module is associated with only one object of other module One to Many (1:M) : One record of a module is associated with multiple records of another module Many to Many (M:M) : Multiple records of a module are related to multiple records of another module and vice versa Moreover, you can add custom relationships between two modules using Custom Module Builder extrension How to read the relationships from the table The first value in the relation is related to the module listed in