Help - identify these water lines

[Super917]

Hello, I was hoping for some help identifying some water lines that are connected in with the cold line going into my water heater. There are 3 lines that I've been unable to identify. I've tried turning off the 1/4 turn valve in the upper right of the photo and my external spigots and all internal fixtures continue to work. If I shut off the yellow ball valve the water turns off to the cold side to my water heater which is expected.

What are the 3 lines in the upper half of the photo? Any help would be appreciated! Thanks

 

[Master Plumber Mark]

That is a feed line going to to the furnace humidifiyer...

 

[Sponsor]

 

[Super917]

Thanks for the quick response Mark! I appreciate it and makes sense as I have 3 Furnace units.