differences in terminology

What is the difference between a pier or a column?

From my research it seems the terms are used interchangeable in many instances. It appears that piers are usually round why columns are stacked. Hence the lally columns. But pier and beam construction seems to include stacked concrete blocks? My Carson Dunlop picture shows them as columns as well.

The foundations are referred to as pier and beam construction. any supporting links would be good.

IMHO they are the same.

I have this bad habit of overthinking things sometimes. Maybe it's good sometimes, but thank you for the response, I've been of the same opinion.