Newbie of Entity Reference - Difference about two similar tasks

I'm sorry for the "stupid" question but i'm new about use of "entity reference".
While i'm building relationship in a view, there are two Entity Reference referred to the same field
Entity Reference: Referenced Entity
A bridge to the Content entity that is referenced via field_companies_entity
Entity Reference: Referenced Entity
A bridge to the Content entity that is referencing Content via field_companies_entity

I always use the first one for my relationships between two contents; what's the difference from the first and the second relation and what can i do with the second one?