What is the meaning of Christmas?

From pagan to Christian; from Christian to commercial…

(As many people travel home for Thanksgiving break, we shall defer the topic of speciesism to a later date, since it is such a popular topic.)

More than 150 countries and regions recognise Christmas as an official holiday. The holiday may have originated as a pagan celebration of the winter solstice, although nowadays it has been associated with the celebration of the birth of Jesus.

As a global cultural holiday, how should Christmas be celebrated? Should secular governments endorse religious Christmas symbols? Will the commercialisation and popularisation of Christmas move it away from its religious meanings?