as follows; as stated below
Formal set phrase used in documents, announcements, or official statements to introduce listed items or details that follow. Often seen in written contexts.
The changes are as follows.
We inform you of next month's schedule as follows.
From 左 (さ, 'left') + の (possessive particle) + 通り (とおり, 'as, in accordance with'). In traditional vertical writing, text that follows appears to the left, hence 'as on the left' came to mean 'as follows'.