PHP is a scripting language that's particularly suited for server-side web development. PHP runtime is generally executed by webpage content.
MySQL is an open source relational database management system. Based in Structured Query Language. It is written in C and C++.
Bootstrap is a popular front-end framework that streamlines website design. It allows for the creation of easy and responsive web layouts.
Cascading Style Sheets (CSS) is a language used most often to style and improve upon the appearance of views. It allows for the separation of presentation and content, and includes the characteristics of layouts, colors and fonts.
Open-source software is a type of computer software whose source code is released under a license in which the copyright holder grants users the rights to study, change, and distribute the software to anyone and for any purpose.