This client is an installer that will download all the files it requires from different sites across the Internet. If you are on a limited usage download plan, please make sure you are familiar with Steam and how it works - check out the official website
for more information.
Compliments of VALVe, this Steam Installer includes all the files you'll need to play Half-Life.
Steam is also a game browser, updater, and buddy messenger all wrapped into one fantastic package with other perks included as well as some yet to come.