There are a few different types of watercolor paint. There are 3 different types of watercolors pan, tube, and liquid. There is also gouache which is a watercolor with a white. Typically you don't use white in watercolor you use the white of the paper. There are two whites which are common Chinese white and bleed proof white. Also some people use masking fluid to preserve the paper's white.
I have used all of these, I think there is value in every water-colorist playing with all the types. What i noticed as benefits for each type
Pan - It takes more of a toll on your brushes. The colors are more student grade level. Which to me are still beautiful. I have heard that student grade will fade more over time.
Tube - This is the one that i have played the least with. I think tubes have great color and color mixing with them is really fun.
Liquid - Is by far my favorite. I have played with dobber painting which was a really fun concept I read in a magazine. I love that i have the color ready to use i add a little water but i don't need to do as much mixing. I think it saves me time.
Keep happy, keep painting.
Myra Lynne Art