Andrew and Vero:

What you have to remember is that Spotlight’s primary objective is to search your files and a small handful of pre-determined web sources. Meanwhile, Alfred’s primary objective is to make you more productive on your Mac with exceptional and powerful features like Clipboard History, System commands, iTunes Mini Player, 1Password bookmarks, Terminal integration, fully bespoke and customisable user-created workflows and much, much more.

Alfred and Yosemite