What is the best way to store change history of website articles?
I presume you're using a CMS. If not, use one. WordPress is a good start.
If you're developing from scratch, the usual method is to have two tables: one for page information (so title, menu position etc.) and then a page_content table, which has columns for page_id, content, and timestamp.
As you save a page, instead of updating a database table you instead write a new record to the page_content table with the page's ID and the time of the save. That way, when displaying pages on your front-end you just select the latest record for that particular page ID, but you also have a history of that page by querying for all records by page_id, sorted by timestamp.
Our client wants us to implement change history for website articles. What is the best way to do it?