No, Facebook and Google are not listening to your conversations. 

That's been a conspiracy theory for several years after some people say they would have a conversation with someone and then a few minutes later see advertisements for products they were talking about. 

I suppose Google could do that with Android phones, but it is highly unlikely the company would go to such lengths when it already knows most everything you're interested in because you've told Google yourself.

When you sign up for Google and for Facebook, you gave the companies permission to track your movements online, which includes any searches you've entered. If you use Google Maps as a GPS, you've given Google permission to know where you are. 

If you watch YouTube, you give Google permission to see what videos you've watched, so it can suggest other videos you might like.

Google stores that search and web history and sells it to third-party companies for advertising revenue. Those companies can then target their advertisements at the people who are most likely interested.

If that still creeps you out, or if you don't exactly trust Google, Facebook and the other companies that participate, then there is another browser you need to see.

www.duckduckgo.com is a search engine that works in all web browsers. Its selling point is that it protects your privacy by forgetting what you search for and doesn't intentionally show you the same search results that it gives everyone.

The search company has become a favorite of internet users concerned about their privacy and who would see their search history. As a trade-off for not selling your search history, you will see advertisements on pages you visit that aren't interesting to you.

DuckDuckGo can be added to any browser, so you can select it as your default search engine.

To install the search engine as a Chrome extension or Firefox add-on, visit the company's website.