Saprophytism is a mode of nutrition where organism (saprophyte) feeds on dead/decaying organic matter (substrate) and the substrate remain unharmed; in this, the saprophyte secretes enzymes on substrate. E.g fungi and some bacteria. Parasitism on the other hand is a mode of nutrition where organisms (parasites) feeds on living tissue of other organisms (host); it’s normally harmful to the host. Parasite secrete enzymes which degrade external tissue of the host, it then penetrate and absorb nutrients. E.g tapeworm in pig, some plants, tick in cattle.