A lens is not a blog. A lens is just a web page, on to which you can put any content you want, from pictures and text, to ebay and Amazon products. It is a good way to get into affiliate marketing if you have little knowledge or resources, and the community is very welcoming. A blog is usually updated on a frequent basis, sometimes with categories and archives of posts. A Squidoo lens doesn't have this. You can of course create as many lenses as you like, either on the same topic or on different topics.
Squidoo is more like separate articles. Excellent in it's own right. But far too clunky to be used as a blog. But a Squidoo lens is very easy to set up and publish.