Here "love" refers the type of love that comes from God, which focuses on the good of others, even when it does not benefit oneself.
# you know that I love you
When Peter answers, he uses the word for "love" that refers to brotherly love or love for a friend or family member.
# Feed my lambs
Here "lambs" is a metaphor for those persons who love Jesus and follow him. AT: "Feed the people I care for" (See: [[rc://en/ta/man/translate/figs-metaphor]])