What coding language to use for coding blocks?

I’m only starting learning dynamo and I’m using dynamo’s example files to learn.

I noticed in one example to make a List a Node was used
The next file, to make the same list a code block was used.

My question is
What coding language is used by dynamo? and to what extent do I need to learn it?

And what is your opinion for using nodes vs code blocks?

Thank you

Here is the DesignScript Documentation,

DesignScriptGuideV2.1.pdf (343.2 KB)