pardon my ignorance, but what's "busking" mean?

back when I used to do saturday market as a vendor my son (then about 10 years old) would always grab up one of my sticks and go busk for half an hour at a time. He'd come back with $50-$100 every time, then he'd spend it all during the next half hour and come back and tell me he was hungry and ask me to buy him something for lunch. When he grew up a bit and didn't look like a tiny kid anymore the tips weren't as good and so he lost all his enthusiasm for it. As a small guy he could hit super high pitched yelps that disappeared when his voice changed, he claimed it was the yelps that drew them in and then the sight of what they thought was a tiny girl rockin a didge (because you couldn't see his face through his long hair) is what emptied their pockets into his tip hat.
So Todd, if you're looking for ways to increase your tips I'd reccomend disguising yourself as a little girl.
I'm struggling to remember the name of a didge player from Rhode Island who would play the boardwalk supposedly ALL DAY EVERY DAY, during the tourist season and he had a book (more of a binder) on display that had all the answers to the questions that people ask you as you play in public and there was more in that book too that made it very interactive for the crowd. Appearantly the book thing helped him to never stop and lose his crowd. Sometimes he would play for several hours between sips of water. His band was Big Blow and The Bushwackers and I loved their music.