Front end and Back end development could be said to be two halves when it comes to web development.Both fields are also very much diverse in their own rights. There are a lot of tools, frameworks and languages out there that aid in development.
Front end development
When we talk of front end we generally mean the part of a website or web app that the user can see or rather that which runs on the browser.
Front end development is largely dominated by web design, where the developer creates and maintains the look and feel of the website or web app.
With basic understanding of the 3 you can become a front end developer, but to become a good developer, take it from me, you need solid understanding of the 3.
There is much more to the front end, there are other concepts and frameworks you need to master to be a good front end developer.
Understanding UX and UI well is what i consider a big plus.Material design concepts are also really important even though you may not end up using any material design framework.
Back end development
The back end of the web opens up to another world of technologies,languages and frameworks. The deals with the behind the scenes part of the website or any app that the user cannot see. It is mainly driven by the database for most apps.
Well you just need to master just one or two of these languages to be proficient at the back end.
Frameworks are also numerous for these languages that help you build a solid back end that take care of the security, speed and scale ability of your app. Some of the most popular ones are Laravel, java spring, django and ruby on rails.
Since the database carries a significant part of the back end it is important to understand SQL and various database management systems like oracle and MYSQL.
Most of the app logic for most apps resides on the back end. Basically, the user or rather the front end makes a request to the back end then it is served with data from this end(back end) when the requested processes have been run.
Most back end programming languages allow you build REST APIs thus one “back end” can be used to serve your native mobile apps, web apps , USSD apps,etc.
The front and back end are a whole world of programming adventures on there own. They complete each other. You can still explore both worlds and become a full stalk developer.