I have been an avid user of Evernote for several years in both business and my personal life. Evernote is often referred to as a "note taking" app, but it is so much more than that. At its core, yes, Evernote is a desktop app, web app and smartphone app that allows you to take notes and have those notes synced across all devices. That's where the power of Evernote starts. Within those notes you can add images, pdf files, Office docs and other file formats. It's a digital shoebox for you to collect your thoughts, files included. Notes can also include checkboxes, bullet points or numerals. This allows you to use Evernote for lists, todo's and reference material. I use it to keep recipes, receipts, articles, lists as well as a filing cabinet for any paper documents I receive and scan.
The other area where Evernote shines is as a web clipper. Evernote provides plugins for Safari, Chrome and Firefox which allows you to clip websites for later viewing. The clipper gives you the option of filing the clipped website into specific notebooks and with specific tags.
The mobile version of Evernote offers several handy features like quick pic uploading, voice notes and scanning of documents and business card. For business use, it's a true swiss army knife of functionality. For personal use, it's a valuable organizational tool that will give you the resource to keep the information in your life organized and at your fingertips.