npm3 resolves dependencies differently than npm2. While npm2 installs all dependencies in a nested way, npm3 tries to mitigate the deep trees and redundancy that such nesting causes. npm3 attempts this by installing some secondary dependencies (dependencies of dependencies) in a flat way, in the same directory as the primary dependency that requires it. The key major differences are: position in the directory structure no longer predicts the type (primary, secondary, etc) a dependency is dependency resolution depends on install order, or the order in which things are installed will change the node_modules directory tree structure ## Example - [Explore on Github](https://github.com/ashleygwilliams/npm-sandbox/tree/master/npm3/example1) Imagine we have a module, A. A requires B. A depends on B Now, let's create an application that requires module A. On npm install, npm v3 will install both module A and its dependency, module B, inside the /node_modules directory, flat. In npm v2 this would have happened in a nested way. npm2 vs 3 Now, let's say we want to require another module, C. C requires B, but at another version than A. new module dep, C However, since B v1.0 is already a top-level dep, we cannot install B v2.0 as a top level dependency. npm v3 handles this by defaulting to npm v2 behavior and nesting the new, different, module B version dependency under the module that requires it -- in this case, module C. nested dep In the terminal, this looks like this: tree You can list the dependencies and still see their relationships using npm ls: npmls If you want to just see your primary dependencies, you can use: npm ls --depth=0