Sacha Greif helps us understand Meteor’s Client/Server split.

One of Meteor’s biggest selling point[s] is the way it blurs the line between client and server. With Meteor, these two environments are no longer separate worlds: they share a common language, and can even share common code! But that blurring of lines comes at a cost: it can sometimes be tricky to figure out what should run where.

Source: What Goes Where: Making Sense of Meteor’s Client/Server Split – Discover Meteor