WhatsApp finally introduced it new pin chats feature to all Android users. The feature was earlier rolled out to beta users.
The feature allows users to pin up their favourite chats to the top of the chats tab. With the feature users are allowed to pin up upto to three contacts on top of other conversations.
With pin chats we never have to worry about scrolling through our numerous conversation for important chats from our close relatives and friends.
Unfortunately now users are only allowed to pin just three contacts, maybe subsequently WhatsApp would allow the pining of more contacts.
You can also disable the pin feature by long pressing the option and disabling the pin button.