How can I learn to read a STEP file and what does it contains?

Hi everyone. I'm a software engineer and this is my first time learning CAD. I'm interested in writing a CAD converter. The first problem is that I cannot seem to find a good guide on how to learn to make sense of all the options and/or components of a STEP file.
So far I know that IGES and STEP files are kind of the industry standard.
If you can point me in the right direction onto how to learn to read a STEP file that will be very useful.
PS. Yes, I would like to make sense of it on a pencil to paper approach first.
Thanks,
new cad user
1 Answer

Here you can learn about
https://grabcad.com/questions/what-is-step-iges
CAD file interchangeability needs to be uniform.
Standard ISO 10303 is trying to solve this problem.
This standard is informally known as “STEP”, which stands for “Standard for the Exchange of Product model data”.
STEP-file (ISO 10303-21) is implementation method of STEP standard that can represent 3D object in Computer-aided
design (CAD) and related information.
Due to its ASCII structure, a STEP-file is easy to read with typically one instance per line.
IGES o Initial Graphics Exchange Specification. IGES was designed as a neutral format for the exchange of CAD models ( U.S. National Bureau of Standards as NBSIR 80-1978. ) Look for ANSI US PRO/IPO-100-1996