What's the difference between practice tennis balls and normal ones?

ok Well pretty much they are the same. You can buy special balls but most places just after a tournament collect the balls and put them in baskets wich will last for hmm about 1 to 1 and a half months lol. The ones u hit with wont have as much pressure because people have already hit with them but at a tournament or a match You get new ones wich will be more lively/ bounce higher, spin more, go faster.

Practice balls are the same as regular balls as far as how they play. A slight flaw in the factory on a batch of balls deems them unable to be sold as regular can. An example would be if the yellow dye came out a very slight shade darker than it should be, they may make 20 thousand balls that have that color practice balls. Another reason may be if there is too much white rubber, or it is too thick. If you order personalized balls for an event, or a club etc. they may sell you 50 cases, but they may make 100. Sometimes practice balls come with a logo. The only drawback would be that you dont get a # on the balls to seperate from other balls. I use them all the time..