introduction_to_vfr_charts.pptx (live.com) Realised that this is for the US but it is very similar in the UK. 1: Controlled Airspace…do not enter unless in contact with the tower 2: Same 3: The 60 over the SFC means that the airspace that is controlled is from ground surface up to 6000 feet. 4: No go zone 5: & 6: These denote larger airspaces. 7. Airspace controlled from 1000’ to 3000’. It is in line with the runway and so keeps VFR traffic clear of landing aircraft. Hope this helps, I’m not an expert.
It’s showing airspaces. The blue circles are the aerodrome controlled areas and the numbers are the applicable altitudes (lower on the bottom-higher on top, logically). The blue regions with dashed lines are restricted/danger areas. On the CAA charts, these have a key that provides more info…
Here’s the same area on an oldish CAA quarter-mill sectional - much more cluttered, much more information: