Hi Catia, welcome to MB
The Rider Waite is said to be one of the most influential decks, that and perhaps the Crowley Thoth? Most tarotists are split between Waite or Crowly as 'masters' f tarot.
Rider is the publisher and Waite the creator, with Universal it is Universal who are the publisher and Waite the designer. But the Rider Waite is more correctly called the Rider Waite Smith. Pamela Colman Smith was the artist used for that deck. The pictures have an eery old quality, they look like they have been copied by hand hundreds of times over and over, so they are not as clear as the Universal printing which is also much more modern bright and colourful and goes into more detail.
Either one is in my opinion brilliant as a starter deck. Many tarotists do not even go any further after that deck, others move on through vastly different ones and explore the Egyptian lines and the Gypsy and French Marseilles heritage lines.
You will love them both, but differently, In fact you may only actually need to have one of them....