Synchroinzation comes in to picture only while using any 
tool. However, it is not possible to use the 
synchronization.

synchronization means to wait till the applied operation 
completes, after that continue the next operation. If we 
conduct testing manually then only we uses this. If we 
conduct manual testing, we should wait till the applied 
operation completes. 

We are not faces these problems manually, i think.

synchronisation is timekeeping which requires the 
coordination of events to operate a system in unison.

synchronization problems may be like..
   
    before you going offline when we use synchronize option 
from tools in ur browser the latest version of pages should 
we get.
    A operation has been done before a status bas fineshes 
its loading
    system is not performing its required operation even 
after finished loading
    when we perform some operation in a web page r browser 
some thing should be roatating/loading/displaying text msg, 
to the user to let the user know system is performing its 
required operation.

Rasul
QA Engineer