QuickTest enables you to expand the scope of a basic test 
or component by
replacing fixed values with parameters. This process, known 
as
parameterization,it greatly increases the power and 
flexibility of your test or
component.



synchronization point is that which handles anticipated 
timing problems by ensuring that QT waits for some times 
until the application is ready for the next step

parameterization is passing multiple input values instead of constant values to verify the functionality.

whenever there is a timegap between the qtp and the application process the test fails, to avoid that we have to use synchronization.
waitproperty "property name", "property value", "time"

Parametrization: Checking the same operations with multiple
sets of data 

Example : For checking the Username in the login window with
multiple sets of data (Characters, Special
Characters,Numbers, varying length of User Name etc)we can
parametrize the User name so that it can select separate
input each time (for characters, numbers,etc) and display
the result. This way parametrization helps you save the time
from repeating the same task with hundreds of different records.

Synchronization: Synchronization helps to handle the Time
gap problems between QTP and the appropriate application by
helping QTP to wait for the application to Invoke 

Example: If the application takes 1-2 min for the data to be
rendered on the screen or for navigating to the next Screen,
QTP will display the results as Fail since in that
particular time period it was not able to fetch the records
or display the Screen, Here the Wait statements helps QTP to
wait till the particular time being mentioned to get the
records.