Understanding Tides

[Northallerton_Boro]

So i understand the difference between low and high tides.

However, take Saltburn for example - High Tide is 4m and Low Tide 0m. What does the 4m mean is it height or distance of the tide?

[tunstall]

https://www.theswimguide.org/2019/12/27/how-to-read-a-tide-table/