Bower vs Composer: What are the differences?
Developers describe Bower as "A package manager for the web". Bower is a package manager for the web. It offers a generic, unopinionated solution to the problem of front-end package management, while exposing the package dependency model via an API that can be consumed by a more opinionated build stack. There are no system wide dependencies, no dependencies are shared between different apps, and the dependency tree is flat. On the other hand, Composer is detailed as "Dependency Manager for PHP". Composer is a tool for dependency management in PHP. It allows you to declare the libraries your project depends on and it will manage (install/update) them for you.
Bower belongs to "Front End Package Manager" category of the tech stack, while Composer can be primarily classified under "Package Managers".
"Package management" is the primary reason why developers consider Bower over the competitors, whereas "Must have dependency manager for PHP" was stated as the key factor in picking Composer.
Bower and Composer are both open source tools. It seems that Composer with 20.2K GitHub stars and 5.54K forks on GitHub has more adoption than Bower with 15.2K GitHub stars and 1.97K GitHub forks.
According to the StackShare community, Bower has a broader approval, being mentioned in 803 company stacks & 396 developers stacks; compared to Composer, which is listed in 95 company stacks and 55 developer stacks.