Bootstrap and WordPress are not the same thing. It’s a bit like comparing oranges to apples.

Bootstrap is a front-end development framework for websites. Its purpose is to make styling a website easier, with built-in support for responsive design.

WordPress is a content management system, which allows administrators to create and modify a website’s content using a visual administration panel.

Often, websites powered by WordPress also use Bootstrap to make styling of the website easier, and implement responsive design easily.