Explain Column drop pattern.
In column Drop pattern a web page with multi-column layout drops a column after each visual breakpoint occurs or screen size gets smaller. Dropped column start stacking down and web page ends with single column layout and other columns stacked vertically down.
In above diagram web page starts with 3 column structure. As the screen size gets smaller the column starts dropping and results into 2 column structure and finally in 1 column structure.