OpenStreetMap + App = OsmAnd!

Hello guys, I'm relatively new to OSM but have found it quite useful and feature-rich since I made the switch to a degoogled phone OS. I now have a question about generating OSM compatible links much like google maps has where I can send a friend a sharable link and when they click it it automatically opens their app (or browser if the app cant be found) to the OSM map with the location under a pin so that they can do whatever with it (most usefully is to "Navigate" to it and get directions)

I'm so new to it though that I don't even know if the concept of a "link" which opens the map exists in the context of OSM. If it does though, I would love to know where I can read up on these links' formats so that I can see how I might generate them from lat+long coords through software.

Many thanks in advance!

Edit: In OsmAnd when I want to share a location, I can select Share then Copy. That will put some text along with a link of the following format in my clipboard:

https://osmand.net/map?pin=35.96296%2C-5.50856#10/35.96296/-5.50856

I get the parts up until the #10. What does the #10 mean and why do the coordinates appear 2 times in the link, once before #10 an once after?