In brief
columns is a shorthand for multi-column layout. Content can flow through successive columns like newspaper text instead of making each column a separate component.
Useful to know
columns is a shorthand for multi-column layout. Content can flow through successive columns like newspaper text instead of making each column a separate component. [1]
For a long article, check reading order and area height. Multi-column flow is not automatically a replacement for grid when building a catalogue of independent cards.
Sources
For further detail and to check the information: