When combined, 圣 (shèng) + 诞 (dàn) + 节 (jié) creates a very logical and literal name: “Holy Birth Festival,” a perfect translation for Christmas.
The most important thing for a learner to understand about 圣诞节 (shèngdànjié) is that its cultural weight is completely different from Christmas in the West.
You will encounter 圣诞节 mostly in urban and commercial settings, and in conversations among younger generations.
People use it to wish each other well, make plans, and comment on the festive atmosphere. The most common greeting is 圣诞节快乐 (shèngdànjié kuàilè)! - “Merry Christmas!”
You'll see 圣诞节 plastered on advertisements, storefronts, and online shopping sites promoting “圣诞大促” (shèngdàn dàcù) - “Big Christmas Sale.” Restaurants will offer special 圣诞节 set menus.
It's very common to hear someone say they have a date or special plans with their significant other for 圣诞节. It's considered a romantic occasion.
For China's small Christian population, 圣诞节 is, of course, a religious holiday. They will attend church services and celebrate its true spiritual meaning, but this is a minority context.