Clock Frequency and Crystal frequency

There may or may not be. The crystal frequency is the natural frequency at which the crystal oscillates. However, its strength is extremely low. Hence you cannot directly use the crystals output in the circuits. You use this as a reference and use a PLL to lock to this reference. The output of PLL can be of sufficiently high strength.

From there, the clock may be divided, multiplied and what not. In its pure form though, the crystal frequency will be equal to the clock frequency.

A quartz clock is a type of clock that uses an electronic oscillator that is regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency, so that quartz clocks are at least an order of magnitude more accurate than mechanical clocks. Generally, some form of digital logic counts the cycles of this signal and provides a numeric timedisplay, usually in units of hours, minutes, and seconds. the world's most widely used timekeeping technology, used in most clocks and watches, as well as computers and other appliances that keep time....

Clock frequency will be generated using any oscillator circuits or 555 timer or Opamps and it will be in square wave form.

Crystal frequency is generated by crystal oscillator which generates frequency by vibrating. And the wave will be in non square shape [almost sine].

clock frequency will be having more sourcing current than crystal frequency......