Reflow
Reflow happens when a browser recalculates the position and geometry of certain parts of a webpage, such as after an update on an interactive site. This tends to be followed by repainting, which is when the browser redraws the webpage to show the resulting visual updates.
See also
- Repaint
- Minimizing browser reflow on developer.google.com
- Understanding Reflow and Repaint in the browser on dev.to (2020)