Data update timestamp ?????

I’m trying to understand the timestamp parameter of shops and nodes in Egypt map, is it the last time this node or place have been updated or not, and if not how to know if that data is new and updated ?

The data is the last time that the data in OSM is updated - it doesn’t necessarily correspond to someone visiting the shop concerned. For example, (to pick a random example) has been updated twice. The first update might have been someone visiting it, or it might have been someone correcting the spelling (which is a perfectly valid reason to update it, of course).

Some editors (Vespucci at least) do flag “this might need resurvey” when it detects a not-recently-edited feature.