An XBRL taxonomy provides an open mechanism for sharing common definitions and supporting information and metadata.
Often a collaboration and governance process is developed around maintaining the particular taxonomy of concepts and using concepts defined in other taxonomies where possible.
Inline XBRL provides a mechanism for companies to report their data in human and machine readable format.
Example
First, a taxonomy is created to collect data against.

Then, three (fictitious) companies all make use of this same taxonomy as part of their sustainability reports.
The first example company is called “CarMaker”.

The next company to report is called “Cloudify”. It also uses the same dictionary (a digital representation of a specific reporting standard).

The third company in this example is called “OutSourcery” and it also reports using the same taxonomy (aka: standards).

Finally, because they all use XBRL and the same taxonomy, it is easy to pull their data together for comparison:
