Site architecture. This term usually refers to the structure of the pages and software part of a website. It helps graphically and visually present all the sections of the website being developed, as well as the relationships and method of interaction between all its components: login screen, user interface, database management system, security functions, API, and so on.
Technology Stack and API. This is a set of software tools for creating the frontend and backend of websites, such as programming languages, compilers, database management systems, libraries, frameworks, APIs, etc. The frontend is the part of the website with which the user interacts directly, the backend is everything else, and APIs (Application Programming Interface) are tools for connecting the frontend and backend of a website and integrating third-party services that extend its functionality, from geotargeting to on-site shopping.