which will start with 512MB of ram and allow it to grow to 1GB, depends how much ram is on your computer and how much you can safely let the server use. I suggest never setting them the same.
For a causal server though this is not necessary and you can often ignore it if only a few friends will be joining.
1
You normally can't launch jar files by double clicking them.
Try creating a .bat file to launch the server.
Then all you need to do is click the bat file (note you may need to run it as admin) and it will launch the server this way.
Optionally, you can state the minimum and maximum ram you would like it to use.
example: "java -jar -Xms=512M -Xmx=1G minecraft_server.1.10.jar nogui"
which will start with 512MB of ram and allow it to grow to 1GB, depends how much ram is on your computer and how much you can safely let the server use. I suggest never setting them the same.
For a causal server though this is not necessary and you can often ignore it if only a few friends will be joining.