In Collabspace, a Property can be understood as a SharePoint Column, Exchange Field, and anything else that is considered a Metadata field. These Properties are used by end users when executing a Search.
Properties are selected as Display Columns and used in Advanced Query Conditions. Because they are used by End Users, it is important to understand how they are represented in Collabspace.
When Collabspace crawls a Content Source, it will bring in all Properties it can find associated with the Content. For Exchange, there is not a large number of Properties, and it will likely be common across most Exchange tenants. Properties like Subject, Body, From, and Sender are shared across companies.
Properties that are crawled from SharePoint Online will have a large amount of variance between companies, because Users and Administrators can customize and create new Properties. Although, there are some common Properties that all instances of SharePoint Online have.
When Collabspace crawls a Property, it will verify if the Property already exists in the Organization. If it does, it will check again to verify if it is the exact same Property (based on GUID). If the Property is not the same property as what has previously been crawled, then it will be added to the Property as a secondary Crawl Property.
A Property can be understood as a label, while the Crawled Properties are what Collabspace has actually crawled from the Content Source.
For example, if a SharePoint Online Content Source has been Crawled, clicking on the Title field will provide a good example of this. In SharePoint Online, there are actually several different Title fields, all associated with different Content Types. However, instead of showing 4 different Titles for the User to choose from (and potentially choose the wrong one), all instances of Title have been bundled together under a Property Label.
When any Property is selected, a panel showing the Name, Type, and Source of the Crawled Properties will be displayed.