Q:

logic: AND and OR statements without parenthesis

In terms of if conditions in programming languages. I do not remember this stuff so I am asking.
I know what (A OR B OR (C AND D)) means
but what does (A OR B OR C AND D) mean?

A:

In general, AND takes precedence over OR.  But like the comments said, it can depend on the language.  For more information on order of operations, see: http://en.wikipedia.org/wiki/Order_of_operations
Another reference, that is Excel specific, also states AND precedes OR in the order of operations.  See here: http://office.microsoft.com/en-us/excel-help/HV080557451.aspx
EDIT:
What this means is that your two statements are equal.
(A OR B OR C AND D)

is evaluated as:
(A OR B OR (C AND D))

