Thanks for the feedback.
I think we're talking about different definitions of "sequence". I was referring to the "Sequences" in the Racket Reference, which can describe infinite sequences. For example, there's in-naturals, which gives you an infinite sequence of "all" natural numbers.
But it's good that you reminded me that there's another "sequence" concept (lists, vectors, etc.) which differs from the "sequence" concept I referred to above. Thanks! I'll also read more of the SICP section you quoted. For the record, I also found SRFI-41 and SRFI-127, but these added more confusion than understanding, as it's unclear to me how they relate to the "sequence" and "stream" concepts in the Racket Reference.
By the way, if you're new to Racket, what do you think about my Racket Glossary project? (*) 
Actually, I started this topic to clear up my understanding for a new glossary entry "Sequences and streams" (or a similar title).
(*) If you want to reply, you can either use the Racket Glossary thread or send me a private message here on the Racket Discourse.