Holidays in American English means a period of time around a cultural event like Christmas or Thanksgiving.
So when an American says “Happy Holidays” it means enjoy the Christmas period. This can sound strange to a person from another part of the English speaking world. “Happy Holidays” is not common outside of North America and people would probably understand it as “Enjoy your holiday” which means go on a trip.
So Remember….
“Happy Holidays” is American English and means enjoy your time off work with your family(you might or might not go on a trip)
“Enjoy your Holidays” is British/Irish/Australian English and usually means enjoy your trip to another place.
Holiday or Holidays
Let’s focus on British English now
We use “to go on holiday”
But
To go on + possessive adjective + holidays
Examples
I was on holiday in Spain last week
He went on holiday to Tenerife.
They go on holiday every summer.
Or
I was on my holidays last week
He went on his holidays to Tenerife
They go on their holidays every summer.
You also use Holidays with “the”
What did you do for the summer holidays?
If you want to talk about holidays in the plural(ie holidays over the years) you can use the verb “to have”
We have had so many great holidays over the years.