Is apple iPhone charger/cable different from iPad charger/cable. Why! Can I use it on my iPad as once the charger/cable did not work and it was not working in iPhone also.

Depends on the iPad model.

Newer iPad Pros (2018 and later) use USB-C instead of Lightning.

USB-C on the left, Lightning on the right.

You can use any Lightning cable with any iPhone from 2012 or later (iPhone 5) and with any iPad from 2013 or later (iPad 4) except the newest iPad Pros.

A charging cable from a new iPad Pro cannot be used with an iPhone, though the charger that comes with the iPad can charge the iPhone with the correct cable.

1. This is a user to user forum, you are not addressing Apple. We users do not make hardware.
2. I've never had any issue with an Apple charger. I have a charger from my original first generation iPad 1 that still works fine.
3. I've had issues with cables fraying at the joins, but never the chargers themselves.
4. If you are getting constant messages of un official devices, check the iPhone's charger port. Sometimes lint can get in there and cause issues with charging. Use a plastic or wooden toothpick and gently try to dislodge anything that may be in there.

I would love it if Apple made a charger cable that would last more than 6 months. It’s beyond a joke. My device is telling me it’s no official when it came with the iPhone I bought in an Apple store. It’s so stupid. You guys need to make better hardware.