Google Sign-In is a secure authentication system that reduces the burden of login for users, by enabling them to sign in with their Google account.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
PHP is a general-purpose scripting language used for web development.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.