Articles = Special Rules & Exceptions.

COMMON EXPRESIONS WITHOUT ARTICLES.

In a number of common expresions, an article is dropped after a preposition.

to school / at school / from school / in/to class / to/at/from university/college

to/in/into/from church, to/in/into/out of prison = hospital = bed

to/at/from work, to/at sea, to/in/from town, at/from home,

for breakfast, at lunch, to dinner, etc.

at night, at midday,

by/car/bus/bicycle/plane/train/boat.

on foot, to go to sleep.

NOTE: the use of home, instead of *to home* (I'm going home)

When you say (I'm going to the home) you are talking about a retirement-home.
(Un asilo de ansianos)

An article can change the meaning of a sentence.

He's in prison. (as a prisoner)
He's in the prison. (perhaps as a visitor)