iPhone is undoubtedly one of the best smartphone in the world. Its design is unique and appealing; no wonder over 100 million people use it. If you’re an iPhone fan, like me, you’ll agree to the fact that the smartphone possesses amazing features. Each model attract the users with its glossy look.
However, if you turn your iPhone 6 or 6s over, you’ll see two horizontal lines on the back – one at the top and the other at the bottom. You may see it as a way of giving the smartphone a stunning look, if that’s what you think, my dear, you’re wrong. There’s something more to it.
Apple – as we all know, the production company of iPhone – always tries to make the iPhone the best smartphone and can never design one without a particular feature.

If that’s the case, why put those two lines on the back? There’s an interesting reason behind it.

Here is the answer:

The two lines serves as the phone’s antenna. Through those lines signals can escape. These lines are also present in the previous models of iPhone but were not visible because previous models made use of glass back panel. Signals easily pass through glass and that’s why most phones use back panels made up of glass, plastic, ceramic etc. The iPhone 6 and 6s make use of aluminum back panel and signals cannot escape through an aluminum. So there must be way for signals to escape otherwise network signal strength will be poor. Already many iPhone users have been complaining about this and so apple decided to put the two plastic lines you see on the back. Those lines create a pathway for signals to escape.

Lines not on iPhone 7

The iPhone 7 do not have these lines as apple replaces the metal antenna with a plastic one. With a new composite metal of aluminum, signals can easily escape thereby increasing signal strength.
And that’s it..

Surprised? you don’t have to. Apple always wants its customers to be satisfied with the most attractive smartphone. I’m sure as an iPhone user that’s what you would want.

http://becometechie.com/the-reason-behind-two-lines-across-back-iphone/