FAQ schema is such type of code and content which you place on your site and that tells to the search engines or crawler that this content is presented on your website in a format of question and answer”. When the content is correctly marked up, then it will help or eligible for rich snippets in the SERP.
Frequently Asked Questions :
Can I mark up a single question and answer?
Yes
Can I put an FAQ content anywhere on the page?
Yes
Is there any limit to the length of an answer?
No, but in SERP result shows approx. 3-4 line related content.
Is there any standard limit to the number of FAQs you can have on a page?
No
Is FAQ Schema helpful in SERP ranking?
Yes, content quality and in-depth content can help in SERP ranking.