The main thing is ensuring all internet traffic is treated equally, basically like you said. ISPs can’t block, throttle, or prioritize content. Some examples:

• Comcast can’t throttle Netflix to make their own Peacock service seem better.
• Providers can’t say that you have unlimited usage of Netflix, but other video services count towards your monthly quota. Some mobile providers in other countries do this.

They also made two other changes. Directly from their press release:

• Safeguard National Security – The Commission will have the ability to revoke the authorizations of foreign-owned entities who pose a threat to national security to operate broadband networks in the U.S. The Commission has previously exercised this authority under section 214 of the Communications Act to revoke the operating authorities of four Chinese state-owned carriers to provide voice services in the U.S. Any provider without section 214 authorization for voice services must now also cease any fixed or mobile broadband service operations in the United States.
• Monitor Internet Service Outages – When workers cannot telework, students cannot study, or businesses cannot market their products because their internet service is out, the FCC can now play an active role.