what does the arrow mean?

the start and end squares go yellow and it shows a little arrow pointing to the right where the notation symbol would be. what does this mean?

It's just a visual tool that you can put on the board that can help you show threats, or act as a reminder, etc. you can remove it by left clicking or drawing the arrow over the two squares again. It's good for calculating if you dont want to visualise it yourself. See hikaru using arrows to his advantage here: https://www.youtube.com/watch?v=KrHr49xGPjg 

thanks for answering but i'm talking about one of the notation symbols that show up on the analysis thing. it's a circle with an arrow in it and the start and end squares go a different colour from usual as well

screenshot ?

Yes

o yea of course it is. thanks

It's a newly added analysis marker

I think that's right - forced move, but the confusing thing is that it always points to the right, no matter which "direction" the forced move is? I think that's what's confusing. To me, at least. Surely there can be a better way to indicate forced move! How about a "1", like, "You only have one move." How many times have we all said that to our opponent in a friendly game? :-)