As attached image, in Label2 I assigned Helvetica 15 font size from XIB. But it shows different font for "Share stories and ideas." and "Send live on or off the app." texts in same label. Why is this happening? why it shows different font size in same label?
I checked and double checked with Photoshop and except for very minor kerning differences the "Share stories and ideas" part is identical in both cases. As for the "Send love on or off..." the font size there is also basically identical, compare the "S" or "e" for example.
Kerning is something that the font render does automatically, see this wikipedia article for more information: https://en.wikipedia.org/?title=Kerning
The "Send love on or off" part visually looks sparser, but that is just an effect from for short words in a row using the wide character "o". Perhaps that is what you are seeing?