In the network resources tab when I check the JS loaded, I get two rows showing size. Both reads 8.5M in development but after bundling for production, it reads 240B & 8.5M

What is the difference in those two values, I mean why two rows of values.

My question is similar to this stackoverflow.com/questions/8072921/chrome-dev-to… but in my case, i've bundled, and also its a huge difference.