An information processing system comprising an equipment unit and an operation unit configured to operate the equipment unit, the equipment unit comprising: a first processing unit configured to execute a first application program having a first representation capability for representing constituting elements (611, 612, 613) of an operation screen for a user interface and configured to provide a request for displaying plural constituting elements (611, 612, 613) of the screen in a first form, said first form depending on the first representation capability; and a first communication unit configured to accept the request and to designate information identifying each respective constituting element to transmit a displaying request for the constituting elements to the operation unit, wherein the operation unit includes: a second communication unit (22, 24) configured to receive the displaying request; and a second processing unit configured to execute a second application program corresponding to the first application program and having a second representation capability for representing constituting elements of the operation screen, which is different from the first representation capability and is rich in representations relative to the first representation capability, and configured to cause each constituting element related to the respective identifying information designated in the displaying request received by the second communication unit to be displayed in a second form (521, 522, 523) different from the first form, said second form being an improved form according to the second representation capability. a first processing unit configured to execute a first application program having a first representation capability for representing constituting elements (611, 612, 613) of an operation screen for a user interface and configured to provide a request for displaying plural constituting elements (611, 612, 613) of the screen in a first form, said first form depending on the first representation capability; and a first communication unit configured to accept the request and to designate information identifying each respective constituting element to transmit a displaying request for the constituting elements to the operation unit, wherein the operation unit includes: a second communication unit (22, 24) configured to receive the displaying request; and a second processing unit configured to execute a second application program corresponding to the first application program and having a second representation capability for representing constituting elements of the operation screen, which is different from the first representation capability and is rich in representations relative to the first representation capability, and configured to cause each constituting element related to the respective identifying information designated in the displaying request received by the second communication unit to be displayed in a second form (521, 522, 523) different from the first form, said second form being an improved form according to the second representation capability. a second communication unit (22, 24) configured to receive the displaying request; and a second processing unit configured to execute a second application program corresponding to the first application program and having a second representation capability for representing constituting elements of the operation screen, which is different from the first representation capability and is rich in representations relative to the first representation capability, and configured to cause each constituting element related to the respective identifying information designated in the displaying request received by the second communication unit to be displayed in a second form (521, 522, 523) different from the first form, said second form being an improved form according to the second representation capability.