Apache is a free and open-source cross-platform web server software.
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.
PayPal is an online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders.
Unix is a family of multitasking, multiuser computer operating systems.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.