After you download Foundation from http://foundation.zurb.com/ (I recommend you go with the complete option), you will see that it contains CSS components and JavaScript components. I placed them all in a folder foundation5 to make it easier to switch releases, or even to maintain a Bootstrap flavor of the site as well.
Here is what you will get with the download:
index.html: This is a web page that shows you the most common features of Foundation.
css: This is a folder containing
foundation.cssandfoundation.min.css, the Foundation stylesheet. Include one of these in the<head>section of your site. In addition, include your own stylesheet. We recommend that you do not modifyfoundation.css. Otherwise, if a new version comes along, you end up overwriting your code.js/foundation.min.js: This is all of the Foundation JavaScript. Put this right before the end of your
<body>tag, after jQuery. Also, do not modify this file.