Low-Level Recording:Is useful if the exact coordinates of 
the object are important for ur test.
Normal recording:Is useful when the recording operations 
that cannot be recorded at the level of an object.

Apart from above points:
Low level record is used to record the session even the 
object is not recognized by the QTP

Normal Level Is Object Context Level ; where QTP recognize 
object with Physical Description Of only interacted object.

Low-Level Recording?enables you to record on any object in 
your application, whether or not QuickTest recognizes the 
specific object or the specific operation. This mode 
records at the object level and records all run-time 
objects as Window or WinObject test objects. Use low-level 
recording for recording in an environment or on an object 
not recognized by QuickTest. You can also use low-level 
recording if the exact coordinates of the object are 
important for your test or component.

1. Normal Recording is also called as context senditive 
record. It is used for recording the actions performed on 
the standard GUI objects.

2. Low Level Recording is used to record atleast some 
minimum operations on the non supported environments.