Can somebody explain the name and function of this icon? I circled it in yellow. It turns red, seemingly when the signal is weak, so I vaguely know its function, but that's not a real explanation. I captured this screen shot from the web.
Also sometimes I have seen next to it dual arrow heads (?), one pointing up, the other down. I haven't seen them lately. Can anybody identify and explain them? Thanks in advance.
Also sometimes I have seen next to it dual arrow heads (?), one pointing up, the other down. I haven't seen them lately. Can anybody identify and explain them? Thanks in advance.
