A Sunrise period takes place before a new top-level domain (nTLD) officially launches. It allows trademark holders an opportunity to apply for registration of their trademarked domain names before general registration of the new TLD is available to everyone. For example, a brand such as Google is able to secure "google", which is their trademark.

Following a Sunrise period is usually a Landrush period. Then, some new TLDs have an Early Access Period before General Availability.

Can I register domains through Dynadot during a new TLD's Sunrise period?

What are the launch phases of a new TLD?