What is the ideal heart rate?

I occasionally exercise soon-to-be daily. I’m also pretty sure something’s going on with my heart.
Now that you know those facts, I’ll go ahead and ask the question
Usually, I walk on a steep incline at/around 4 mph. While I’m doing this, my heart rate is normally at/around 185. If I am not hurting and decide to jog for a minute or two, it’s around 205–210.

Where should my heart rate be?
I only ask because I never see anyone else’s heart rate that high. Thanks guys!