Maybe you’re familiar with the LAMP stack? Linux, Apache, MySql, PHP. That’s been a pretty common way to serve websites for many years (circa 1998?). But things have changed, technologies have changed, and it’s not 1998 anymore. IE6 is dead, nested tables are dead, and the LAMP stack is the Old and Busted. The New Hotness is the MEAN stack, MongoDB, ExpressJS, AngularJS, and NodeJS. This new stack of technologies is what many new web apps are using these days.