I am a beginner in web development and I recently started working with Twitter Bootstrap, I know it uses Glyphicons which I already know how to use. But I also came across Font Awesome which says that it is built for Bootstrap.
What are the differences between the two? I mean is one an alternative for the other? Or should you use them in different places?
In Bootstrap 2.x.x Glyphyicons were in image format, hence you can't increase the size, change the color, background-color, etc easily. However, font-awesome gives you scalable vector icons that can instantly be customized — size, color, drop-shadow, and anything that can be done with the power of CSS.
Font-awesome is really an alternative for Glyphyicons which is getting updated time-to-time with new icons. Fat and Mdo are planning to integrate Font-awesome in bootstrap version 3 as a replacement for Glyphyicons.
My suggestion is you use bootstrap with font-awesome. First include bootstrap css and then Font-awesome css, so that the Glyphyicons will be override by font-awesome.
UPDATE
In bootstrap version 3.x.x glyphicons become font format, which will render nicely even in 12px font-size. If you're using the latest version of fontawesome, i.e. 4.01, you can use both glyphicons with fontawesome.