No, these balls are not legal for use in competition. This is because these balls are sold as practice balls so the manufacturer does not make a request to R&A and USGA that they be added to the list of conforming Golf balls, if they are not on this list, you can't use them.
But I have seen people play with them in club competition and everyone seems oblivious that they are illegal.
The 20Xi logo on the Tiger Woods hat is for golf balls. It is the logo for Nike 20XI Golf Balls.
No, logos on golf balls do not affect the playability of the ball in anyway.
If one does not mind shopping online, there are numerous websites that offer golf balls with a logo. Par Golf, Zip Line Golf, Street Directory, Cafe Press and Branders all have online sites where one can purchase golf balls with a logo.
Golf balls that feature a corporations logo are bought from places such as Corp Golf USA, 4 Imprint, Imprinted Golf Store, Par Golf, and Polara Golf who do the printing prior to final sealing.
Most golf balls are white, with a small logo of the company that manufactured them on the ball. Golf balls are available in other colors to improve visibility when playing in low light conditions, or in cold areas where the ground might be frosty.
It's a logo for Nike's RZN golf balls
There is no difference between golf balls that amateurs and professionals use. Yes you could say that professionals only use the high end golf balls, whereas amateurs use any ball they buy. The professionals may have their name, a sponsors logo or special numbers on the ball. But in terms of playability there is no difference.
An average pro shop will probably be displaying about 1000 but they are usually sold in packs of 3 or 12 they will probably have a lot more balls in storage as well. Also many pro shops will sell single balls that they found on the course or have the club logo.
You can find images of the golf logo at the official PGA website. You can also locate golf logos on popular golfing website such as Golf Digest and Golfsmith.
It is a golf ball that has the logo of a resort/golf course printed on the ball.