Afterwards and By and by

Afterwards adverb - Happening at a time subsequent to a reference time.

By and by and afterwards are semantically related In some cases you can use "By and by" instead an adverb "Afterwards".

Nearby Word: afterward

By and by adverb - At or within a short time.

Afterwards and by and by are semantically related in later topic. You can use "Afterwards" instead an adverb phrase "By and by", if it concerns topics such as afterward.