How to perform wait in selenium

Using the thread,sleep user can pause the currant thread.But handling a simple waiting for a element is a bit advance thing,
Because this need more resources from the computer(mainly ram usage)

1).Thread.Sleep(5000);

Using the webdriverwait:

2).WebDriverWait wait = new WebDriverWait(<webdriver>,<timetowait>);

eg:

   WebDriverWait wait = new WebDriverWait(WebDriverInti.driver, TimeSpan.FromSeconds(5000));

   wait.Until(ExpectedConditions.ElementExists(By.XPath("//*[@id=\"rdiv\"/h3/a")));

Using webdriverwait: (More advance way)

3).

WebDriverWait wait = new WebDriverWait(WebDriverInti.driver, TimeSpan.FromSeconds(5000));

wait.Until<IWebElement>((d) =>

            {

              IWebElement element = WebDriverInti.driver.FindElement(By.XPath("//*[@id=\"rso\"]/div[2]/li[1]/div/h3/a"));

                if (element.Displayed && element.Enabled)

                {

                    return element;

                }

                return null;

            });


Using webdriverwait: (Friends way)

_driver = new ChromeDriver(@"C:\ChromeDriver", options, TimeSpan.FromSeconds(180));