If I want to make an online shopping website (like amazon) what do i need to know?

Generally, people get a standard "web shop" ecommerce style program and just customise that to their requirements.

There are many, both free and paid/subscription ones.

I've used Zencart for our business for quite a few years; it's free and excellent community support.
https://www.zen-cart.com/

There is no reason you cannot create an ecommerce site from nothing, but it will take a _lot_ of work and if the target is to get a site online and sell things, using and customising an existing package is far faster and easier.


As per the olds saying - Don't re-invent the wheel.
(I'm a professional programmer, but I'd rather put my time and effort into original, saleable projects than recreate standard items that are available free).


To make you own you need HTML and PHP to start with.
SQL (to work with Mysql via php) is also essential.

Javascript can make the site more interactive - but a lot of new programmers add so much it destroys the site usability.

(Ideally, the visible content of a web page should be at least 60% of the total download size of the entire page and any linked libraries etc. - some so-called web developers create pages with 15% or less; they take ages to load and the site is generally unresponsive).


Web design is debated term. Some people consider it to be strictly appearance but as far as I am concerned it covers every line of code and everything about how the site functions.

Compare to eg. a Car design - every component of the body, suspension, engine, gearbox etc. has been designed and assembled to make it what it is; leave a bit out and it does not function.


You could consider it as artistic design and functional design - both have to be done properly for it to sell and work as it should.