Most of today's Intel Core i5 and i7 processors have Turbo Boost capability. You can check if your Intel processor has this ability by looking for the term Intel Turbo Boost Technology in the specifications for your processor at the Intel website.
Processors with Turbo Boost have two listed clock frequencies: a base frequency and a maximum Turbo frequency. The base frequency is a number that is always lesser than the max turbo frequency.
As you go about using your computer, it can be fun to monitor when your processor switches to Turbo Boost mode and runs at what Turbo frequency. One way to do this is to download, install and run the Intel Turbo Boost Technology Monitor program from here.
The height of the vertical bar shown by the program represents the current frequency of the active cores of your processor. As long as the frequency is within the base frequency it is colored in dark blue. When it shoots beyond base frequency to the Turbo Boost frequency, that portion is shown in light blue color. Only when the processor is in Turbo Boost mode, the frequency number is displayed (3.6 GHz in the above figure). A green leaf, symbolizing energy saving, is displayed when not in Turbo Boost mode, since the processor draws full power only in that mode.
Tried with: Intel Turbo Boost Technology Monitor 2.6.2