Proxies have long become a core tool for traffic arbitrage, SEO, scraping, e-commerce, automation, and multi-accounting. Yet in practice, many people still get confused by proxy types and choose a solution based not on the task at hand, but on price or random advice from chat groups. In this article, we break down in simple terms how datacenter, ISP, residential, and mobile proxies differ, when you need static or rotating proxies, what sticky session means, why SOCKS5 is considered one of the most flexible protocols, and how to build a reliable infrastructure without unnecessary mistakes. We also take a separate look at why SimplyNode is convenient as a single platform for residential and mobile proxies, and how the SimplyNode + Cloaking House setup helps test campaigns more safely, work across different GEOs, and reduce the risk of account bans.