Can someone tell me why are they using " p .italic" and not just ". italic"?

Answer 1

p.italic apply to all elements inside paragraphs with class="italic"
.italic apply to ALL elements with class="italic" in the page, not only inside paragraphs.

Answer 2

cause that "p" no afect the css function and give u a reference for know what element are styling without saw the html code

Answer 3

Writing only .italic doesn't tell CSS which element it applies. By writing p.italic we are telling CSS that we want to make whole paragraph italic