When do we use setExperimentalOptions in selenium chrome options?

Can someone Please explain me the last two lines of code.I have searched many sites for the answer but there is no clear explanation.

        ChromeOptions options = new ChromeOptions();
        HashMap<String, Object> chromePrefs = new HashMap<String, Object>();
        chromePrefs.put("profile.default_content_settings.popups", 0);
        options.setExperimentalOptions("prefs", chromePrefs);