The difference between Alter and Edit

Alter as a verb (transitive):

To change the form or structure of.

Alter as a verb (intransitive):

To become different.

Alter as a verb (transitive):

To tailor clothes to make them fit.

Alter as a verb (transitive):

To castrate, neuter or spay (a dog or other animal).

Alter as a verb (transitive):

To affect mentally, as by psychotropic drugs or illness.

Alter as a noun (especially, in the plural):

One of the identities or personalities of a person with multiple personality disorder / dissociative identity disorder.

Edit as a noun:

A change to the text of a document.

Edit as a noun (computing):

A change in the text of a file, a website or the code of software.

Edit as a noun (comedy):

An interruption or change to an improvised scene.

Edit as a verb:

To change a text, or a document.

Edit as a verb (transitive):

To be the editor of a publication.

Edit as a verb (computing):

To change the contents of a file, website, programme etc.

Edit as a verb (biology):

To alter the DNA sequence of a chromosome; to perform gene splicing.

Edit as a verb:

To alter a film by cutting and splicing frames.

Edit as a verb (comedy):

To cut short or otherwise alter an improvised scene.