An equity round is the broader term for any priced equity issuance, Series Seed, Series A, Series B, growth rounds, and so on. Each issues a new share class with negotiated rights (preference, anti-dilution, board, information, voting). The price-per-share, the share class, and the protective provisions are the three dimensions investors negotiate hardest.
Equity rounds are the cleanest cap-table event but also the most expensive in legal fees and the most disruptive in valuation visibility (every employee can do the math on the new strike price).