What does " writing system" refer to?

[japanjapan]

Dear teachers,
please look at the following paragraph.
When early humans began farming, it was a revolutionary change in human life. It was thousands of years later that people developed a writing system. In less than fifty years people have developed computers that can do most of the things humans can do.
What does " writing system" refer to?
according to the text, the "writing system" was invented about 50 years earlier than the computer was invented. what is it?

[Temico]

according to the text, the "writing system" was invented about 50 years earlier than the computer was invented. what is it?

Which text are you referring to? The passage which you quoted does not state that "the "writing system" was invented about 50 years earlier than the computer was invented".

[Robert B. Mercer]

... people developed a writing system....

A "writing system" is a system, a method, a way, to write.

So, a writing system means: letters, writing, Chinese characters, etc.

But in that paragraphy, you are right--writing systems were invented... 3000 years ago? Not 50 years before computers...