Application Architecture

In the early days of computers, applications were developed as a single file (referred to as an executable file) that would need to be run on the computer on which you wanted to use the application. This single file had all the instructions and data required for the application, and it would write and read some data from files on the computer's hard disk.

As applications become more complex, it became difficult to write all the instructions in a single file. Programmers started to distribute instructions across files, and mechanisms were designed to have multiple files work together. As applications became even more complex, the programs would run on different computers altogether, and mechanisms were designed to have programs interact with each other across computers over a network.

Application architecture is the science of designing how an application with multiple programs is structured, and deciding the programming languages for each program. The way the program interact or communicate with each other whether they run on a single or multiple computers connected to a single network.