Google Click ID (also known as GCLID) is a parameter assigned to the Google Ad and is passed in the URL to track clicks and conversions. The GCLID is only used in Google Ads and is enabled by turning on auto-tagging in the settings. It is used to tie your Google Ads with your Google Analytics account so that the clicks and the conversions can be tracked.

Google Analytics keeps track of website visitors as users, and it uses the Client ID stored in the browser cookie to determine it. Google Analytics stores _ga cookie in the user's browser and the browser sends cookie data to a web server every time it makes a request. To view your Google Analytics (GA) cookie for a specific site, you may use developer tools available on your browser to view them. For example, on Google Chrome you may click the F12 key -> Applications Tab -> Cookies to view them. An example of "_ga" cookie looks like below:

Bounce rate is a metric used to measure the percentage of visitors leaving your website after only 1-page view and nothing on the website. If a visitor lands on a web page and bounces back with no additional engagement after viewing the landing page, you have a bounce rate of 100% for that visit. By improving the quality of your website, you can lower your bounce rate and increase pages per session.