a) Synchronization points enable you to solve anticipated timing problems between the test and your application. For example, if you create a test that opens a database application, you can add a synchronization point that causes the test to wait until the database records are loaded on the screen.
b) For Analog testing, you can also use a synchronization point to ensure that WinRunner repositions a window at a specific location. When you run a test, the mouse cursor travels along exact coordinates. Repositioning the window enables the mouse pointer to make contact with the correct elements in the window.

[Source: JAGAN MOHAN "Interview questions bible"]

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