Serena Williams is the best woman tennis player in the Open era.
She's won more, lasted longer, and overcome a lot to make that claim. And she claimed the Australian Open, over her big sister Venus. I predicted Serena would win when she beat Johanna Konta, and I also hoped she wouldn't have to play Venus to do it. But she did. And she won gracefully and Venus lost gracefully, after a strong 6-4, 6-4 effort.
This Washington Post article is pretty good about what it means.
Serena Williams stands alone atop modern tennis after winning Australian Open
"Venus Williams would hug her for a long time and then get to tell the audience, “That’s my little sister, guys.” Serena Williams would amass her 23rd Grand Slam title, beyond all the teeming horde of players who have tried the sport since it shed its amateurs-only status in 1968. She exceeded Steffi Graf’s 22, just as she had exceeded the 18 of both Chris Evert and Martina Navratilova and the nine of Monica Seles. Only Margaret Court’s 24, gathered mainly in the years before the Open era, remains ahead of Williams, who has seven Australian Open titles, seven Wimbledon titles, six U.S. Open titles, three French Open titles and a fresh, new stay at the No. 1 ranking she lost in September to Angelique Kerber."