Embedded Timelines rate limits


“Embedded timelines are not subject to traditional Twitter API rate limits, and are designed to scale with your site as your traffic and audience grows.”

What that means? There are no limits at all, or are they different? Can someone quantify this “scaling”? I’m planning to develop a Timeline that could show several hundreds keywords (in Streaming API they are limited to 400) and I’m interested in understand this.
Thanks in advance