There are many differentiates between those 2 famous languages.
Besides the names phrase of the one is added "script" words.
There are have a crucial part of functions (process) that someone has told me, and I started to dig it deep!
So, let's start with that main issue!
There's called a way of processing jobs, later we called it as thread.
Basically, thread is a way of processing our instructions in an independent process in our processing unit.
It creates our code not readable from left right and top to bottom anymore, we can schedule our instructions and process it as we need, we can stop or destroy the threads without losing another process that has been running, controlled by us!
In a brief description, it's like "creating a new bridge" to process our instructions.
Multi-thread means, we can initiate many threads in a single time, it's such as create many bridges in the one time, so that many streams can flow over every bridge.
Single-thread, it pretty much same as thread, that only does a single job or process to read our instructions. It only creates one bridge of data and it's a lightweight process.