Linearity is a system property with a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input is multiplied by a constant, the output is multiplied by the same constant. Additivity means that the response to multiple inputs is their individual responses' sum. A system that has both homogeneity and additivity properties is classified as a linear system. Linear systems include circuits with resistors, capacitors, and inductors that adhere to the superposition principle. Conversely, systems that fail to obey the linearity equation are classified as non-linear, often including devices like rectifiers and diodes. A causal system is characterized by a current response independent of future input values. An example can be a car's movement, which can not predict future driving actions. Noncausal systems, such as ideal filters, can't be physically realized and do not follow the principle of causality. Dynamic systems show memory, where the output is affected by both past and future inputs. Static systems are memoryless or instantaneous systems where the current output is solely based on the present input.