@trondsb1
Arrows mean the directions towards where the wind is blowing or the waves and swell are heading.
Then for wind the numbers are the wind speeds.
For waves and swell the numbers are the significant heights.
All figures according to the units displayed in the left column and that you can change.
See further information
https://community.windy.com/topic/17449/swell?_=1712820582349