https://www.w3schools.com/whatis/whatis_fullstack.aspA full stack web developer is a person who can develop both client and server software.
In addition to mastering HTML and CSS, he/she also knows how to:
Program a browser (like using JavaScript, jQuery, Angular, or Vue)
Program a server (like using PHP, ASP, Python, or Node)
Program a database (like using SQL, SQLite, or MongoDB)
Popular Stacks
LAMP stack: JavaScript - Linux - Apache - MySQL - PHP
LEMP stack: JavaScript - Linux - Nginx - MySQL - PHP
MEAN stack: JavaScript - MongoDB - Express - AngularJS - Node.js
Django stack: JavaScript - Python - Django - MySQL
Ruby on Rails: JavaScript - Ruby - SQLite - PHP
Advantages
The advantage of being a full stack web developer is:
You can master all the techniques involved in a development project
You can make a prototype very rapidly
You can provide help to all the team members
You can reduce the cost of the project
You can reduce the time used for team communication
You can switch between front and back end development based on requirements
You can better understand all aspects of new and upcoming technologies
Disadvantages
The solution chosen can be wrong for the project
The solution chosen can be dependent on developer skills
The solution can generate a key person risk
Being a full stack developer is increasingly complex