How did historians learn about the past?

Historians gathered a lot of sources,than they categorize it:written(documents,newspapers,letters, diaries..) or non-written(fossils, artifacts, tums,monuments...).By evaluating sources they asked questions and time of origin:
Questening a source(the questions asked were):
What kind of source is it?
When was it written?
Why was it written?
Who did it write it?
Where/when was it found?
Time of origin(when was it created):
Primary
Secondery

After that they interpreted sources.After all of that was done and thy were sure that everything they found is correct hey shered their findings.