A..................circuit is an interconnection of flip-flops and gates.
A sequential circuit is an interconnection of flip-flops and gates.
Combinational circuit is an interconnection of logic gates but sequential includes both flip flops and logic gates and part of sequential circuit is a combinational circuit.
Flip flop is a sequential circuit which generally samples its inputs and changes its outputs only at particular instants of time and not continuously. Flip flop is said to be edge sensitive or edge triggered rather than being level triggered like latches.
Sequentiallogic is a type of logic circuit whose output depends not only on the present value of its input signals but on the sequence of past inputs, the input history as well.