The hit is painted in terminal_image<-isearch_style and the other matches on the screen in terminal_image<-isearch_other_style. A search owns that feedback while it runs, so the selection's own matches (see terminal_image->selection) are not shown as well; leaving a search with the hit selected hands them straight over. What it reports as it goes -- through visual->report, so where that lands is the window's business -- says which of the matches it is on and how many there are, as (3/4). Those are counted over the whole buffer, and from its start whichever way the search is going, so a search backwards begins at the last of them and counts down. Every place the string occurs counts, overlapping ones included: a repeat steps a single character, so those are places the search can get to.

^S, ^R	The next hit, forwards resp. backwards
Backspace	Drop a character and search again
^W	Take the word behind the hit into the search string, along with whatever separates the two, so that pressing it again walks on word by word. Not across a line: a search string with a line break in it matches almost nothing
M-c	Turn terminal_image<->exact_case on or off
M-w	Turn whole-word matching on or off, as terminal_image<-match_word reports it
^G	Give back the view and the selection the search started from
Escape, Return	Leave the search with the hit selected
Any other key	Leaves the search, and then means what it usually means

A search that started from a selection (terminal_image->isearch_selection_backward) differs in one way: ^G puts that selection back rather than leaving none.

Two things differ from editor->isearch_forward. Escape and Return are swallowed rather than passed on: an unhandled key here reaches the process on the terminal, and leaving a search is no reason to submit a line to a shell. ^C is the exception that proves it -- it ends the search and then interrupts, or a search started over a running program would trap the interrupt.

Running out of hits only says so; the attempt after that starts over at the far end of the buffer. A search refuses to start on the alternate screen, whose lines are not in the buffer, and an application that claims the screen ends one that is running.