Can you let me know more about Index Funds

I am a regular reader of your website since 2015. My request is, could you please throw some light on passively managed index funds and their scope for small scale Indian investors. I read an article in an American journal recently. It says that a passive fund has only market risk but no 'fund manager's risk'. Where as an actively managed fund has market risk as well as fund manager's risk.! I loved the above observation. I will be obliged if you could include this subject in your blog for your readers?