Above is the search result for querysave iphone battery
These words are bold. Why they are bold?
Did the admin set the meta description in that way or google will highlight the words in meta description which match the search query?
Words change bold based on search keywords. I think you search keyword contains these following words conserve iPhone and battery. So, That words are displaying bold.
You, Don’t need to set meta description with bold tags.
But My search query is save iPhone battery
But the letters in bold are conserve, iPhone, battery
battery and iPhone words are in my query but not conserve
I think the answer to this is different from what you answered
Conserve is synonymous of Save. So, Conserve looking bold in search results.
Same Words or Synonymous with the words also looking bold in search results.
I agree with @svignesh1994
Google also highlight synonymous words into search snippet.