With RSU (restricted stock units) the price is not given; the number of shares is. Basically, you are granted a number of shares to vest on a particular date (the vest date is the date the shares are yours).
For public companies, the vest date is also the release date, which is when the shares are recognized as income. You have to pay taxes when they are released, which is basically 25% federal tax plus whatever your state's tax rate is for this (10% in CA). To pay the taxes you can either deposit cash to cover the amount and keep the shares, or sell some fraction of the shares on the release date.
If you keep the shares, then any gain after the release date is taxed as capital gains. Basically, from a tax perspective it's equivalent to the company paying you cash on the release date equal to the stock price of your shares and you buying shares with it.
For public companies, the vest date is also the release date, which is when the shares are recognized as income. You have to pay taxes when they are released, which is basically 25% federal tax plus whatever your state's tax rate is for this (10% in CA). To pay the taxes you can either deposit cash to cover the amount and keep the shares, or sell some fraction of the shares on the release date.
If you keep the shares, then any gain after the release date is taxed as capital gains. Basically, from a tax perspective it's equivalent to the company paying you cash on the release date equal to the stock price of your shares and you buying shares with it.