A pump for producing and dispensing foam, comprising: an annular outer compartment, forming an air chamber, having an inlet and an outlet, an annular inner compartment, forming a fluid chamber, having a fluid inlet and a fluid outlet, the fluid inlet being in fluid communication with a fluid containing reservoir, a foam generating member for generating turbulence in air and fluid passing therethrough to produce foam, the foam generating member positioned downstream from the annular outer compartment outlet and the fluid outlet to receive fluid which has been discharged through the fluid outlet and air which has been discharged through the annular outer compartment outlet, a discharge outlet downstream from the foam generating member open to the atmosphere for discharge of any air, fluid and foam discharged outwardly through the foam generating member, the pump comprising a piston chamber-forming member and a piston-forming element cooperating to define the annular outer compartment and the annular inner compartment, the piston-forming element being reciprocally slidable with respect to the piston chamber-forming member between a withdrawal position and a retracted position, characterized by: whereby moving the piston-forming element in a withdrawal stroke from the retracted position to the extended position decreases the volume of the annular outer compartment, thereby pressurizing the annular outer compartment forcing liquid and air through the foam generating member and whereby moving the piston-forming element in a retraction stroke from the withdrawn position to the retracted position increases the volume of the annular outer compartment, thereby drawing air into the annular outer compartment. an annular outer compartment, forming an air chamber, having an inlet and an outlet, an annular inner compartment, forming a fluid chamber, having a fluid inlet and a fluid outlet, the fluid inlet being in fluid communication with a fluid containing reservoir, a foam generating member for generating turbulence in air and fluid passing therethrough to produce foam, the foam generating member positioned downstream from the annular outer compartment outlet and the fluid outlet to receive fluid which has been discharged through the fluid outlet and air which has been discharged through the annular outer compartment outlet, a discharge outlet downstream from the foam generating member open to the atmosphere for discharge of any air, fluid and foam discharged outwardly through the foam generating member, the pump comprising a piston chamber-forming member and a piston-forming element cooperating to define the annular outer compartment and the annular inner compartment, the piston-forming element being reciprocally slidable with respect to the piston chamber-forming member between a withdrawal position and a retracted position, characterized by: whereby moving the piston-forming element in a withdrawal stroke from the retracted position to the extended position decreases the volume of the annular outer compartment, thereby pressurizing the annular outer compartment forcing liquid and air through the foam generating member and whereby moving the piston-forming element in a retraction stroke from the withdrawn position to the retracted position increases the volume of the annular outer compartment, thereby drawing air into the annular outer compartment. whereby moving the piston-forming element in a withdrawal stroke from the retracted position to the extended position decreases the volume of the annular outer compartment, thereby pressurizing the annular outer compartment forcing liquid and air through the foam generating member and whereby moving the piston-forming element in a retraction stroke from the withdrawn position to the retracted position increases the volume of the annular outer compartment, thereby drawing air into the annular outer compartment.