Are term_taxonomy_id and term_id the same? [duplicate]

No, they are not the same.

It is quite clear looking at the table names:

term_id is the ID of a single term, whatever taxonomy it belongs to. The other information in the table term_taxonomy is related to the term – the slug, the title etc.

term_taxonomy_id is the ID of the relationship between a single term and a taxonomy, and does not contain any other data.