They do fundamentally the same things but with very different approaches and tradeoffs.

Webpack and Vite are very different approaches to the same problem with different tradeoffs[0][1]

[0]: namely, webpack and its inevitable successor rspack, are way more flexible and arguably powerful but at the cost of higher complexity and more proprietary features like the webpack/rspack specific runtime. Superior in asset handling though, in many respects, and the high level of optimizations you make once you hit a certain complexity threshold is greater than what Vite/Rolluo has currently without extensive custom plugins

[1]: Vite or Rollup is most likely what most projects need. I’d recommend always starting there, as most of the advanced and flexible features of webpack/rspack are very much not what most need