This is the configuration needed to run npm packages on the browser,i.e. on the front_end. This is simpler to work with than when using bundlers.
Bundlers like webpack, are used to package the entire application's files (* .ts and *.js) files into one file which is then launched from the webpage
Browserify works to reduce the effort of running your NPM packages from node js directly.
The common way of running npm packages is by creating a file, index.js and using the command node index.js run it.
Browserify compiles your node file(s) into one single js file. The file is globally referred to as bundle.js (for superficial purposes)but you can tune the name to your own usage.
For more information on how browserify works, head over to the browserify official documentation here