The UI displays differently on large and small screens

I’m learning about unity but am having a issue.

When I leave the Unity window on the Macbook screen, the layout is broken, but when I move it to a larger screen, it displays normally.

What it causing this?


in screen macbook

in larger screen

If I type it, the text would be pretty long, but I managed to find the video from where I learnt this, I had also watched 2-3 other videos concerning this topic and this was the best:

This is nature, because UI units is pixel. We can make our screen to be ‘responsive’ by using Unity Canvas Scaler, set it to reference resolution. Reference resolutions usually comes by the most popular resolution such as 1920x1080 or 1080x1920 if you are on mobile.

Don’t forget there is a feature called anchoring to snap which corner the UI should be