What's the difference between "memory" and "memory footprint" fields on Chrome's task manager?

I'm using Chrome 64 and noticed that there's two fields called "memory" on Chrome's task manager. See the picture below:

I can't find any explanation of the difference between these fields on Chrome, there's no tooltips available (at least not on macOS). The "memory footprint" field seems to be new, because I don't recall seeing it before yesterday.

In Chrome, the memory column represents Shared Memory + Private Memory. If you enable those two columns and add the numbers you will find they match the Memory column. In the task manager or activity monitor of the computer you can see that these values match the Shared Memory Size and Private Memory Size.

The Memory Footprint column matches the number of MB reported for the Memory column of the process within the Task Manager or Activity Monitor.

Real Memory in a Mac's Activity Monitor maps to the RSS (Resident Set Size) in Unix. The link below explains this.

https://forums.macrumors.com/threads/memory-vs-real-memory.1749505/#post-19295944

The Memory column on a Mac's Activity Monitor roughly correlates to the Private Memory Size, however it seems to be calculated slightly smaller. This column will match the Memory Footprint column in Chrome.

Please note that this answer references Mac because that's what I'm currently using. The column names and answer would change slightly for Linux and Windows system monitor and task manager.