Does a cryptosystem provide unconditional security if and only if it provides perfect secrecy? Is unconditional security and perfect secrecy one and the same thing, i.e a cryptosystem provides unconditional security if and only if it provides perfect secrecy ?

I've wondered about the above and seen that the one-time-pad provides unconditional security in terms of perfect secrecy. Does this hold in general ?
Yes, in context of encryption the two terms have the same meaning, i.e. even an unbounded adversary cannot succeed in breaking the secrecy of the scheme. 

Note that there may be other primitives which also provide unconditional security with respect to some other notions, such as information theoretically secure message authentication codes with respect to unforgeability.