Password protecting certain WP pages with .htaccess

Hi, I am using wordpress as a CMS for a client and they require part of the site to be password protected for members. I don’t need any signup page or anything, a username and password will be given to each member.

What is the best way to do this? I know how to use .htaccess to protect a folder on my site, but how can I protect only some parts of a wordpress site?