1. A label and tag printer comprising: hardware; firmware configured to control functions of the label and tag printer, the firmware including first source code to perform an initial function of the label and tag printer, the initial function being a function to print a first format of an image on a label, and second source code to perform an extended function of the label and tag printer, the extended function comprising at least a function to print a second format of an image on a label; a first memory storing an application program, at least one application program interface configured to directly interface with the firmware, the application program including a first software command to instruct performance of the initial function and a place holder, the extended function being formatted as the at least one application program interface, wherein boot code is stored in the first memory and is executed during a boot-up process of the label and tag printer; a processor which is configured to: call the first source code, in accordance with the first software command; perform the initial function, by controlling the hardware in accordance with the called first source code; introduce a second software command to instruct performance of the extended function to the place holder; call the second source code, in accordance with the introduced second software command; perform the extended function, by controlling the hardware in accordance with the called second source code, build an image buffer on the second memory after the boot-up process of the label and tag printer, generate print data corresponding to the image, by executing the application program on a virtual machine, render the print data to image data, corresponding to the first format and the second format, based on the first source code and the second source code, respectively, write the image data on the image buffer, control the hardware to print the image corresponding to the image data on the image buffer, and purge the application program from the second memory and download the application program to the first memory after operation of the label and tag printer is concluded; and a second memory having a higher operation speed than that of the first memory, wherein the processor is further configured to expand and write the application program, the at least one application program interface, the virtual machine, and the firmware, which are stored in a compressed format in the first memory prior to the boot-up process of the label and tag printer, on the second memory in an uncompressed format, after the boot-up process of the label and tag printer.