After Birchas Hashachar, we recite Karbonos. The Gemara in Megillah relates that Avraham asked Hashem how Klal Yisrael would achieve forgiveness once the Beis Hamikdash is destroyed if we can no longer bring Karbonos. Hashem replied, when Klal Yisrael recites the pesukim of Karbonos, I will consider it as if they offered the Karbon, and I will forgive their sins.
Some sages maintain that Karbonos are not obligatory and rather just minhag. However, some assert that parshas Hatamid and parshas Haketores are so crucial that they take precedence over most pesukei d'zimra! (אבני ישפה ע׳ קי״ט). Many poskim hold that, at a minimum, it is obligatory to say parshas Hatamid daily. (S”A harav 48.1, Rema 48.)
Korbonos comprises several subsections:
הכיור
תרומת הדשן
התמיד
קטורת
איזהו מקומן
רבי ישמעאל
הכיור- We say the pesukim that relates to the kiyor because the Kohanim were not able to perform any avodah in the Beis Hamikdosh before washing their hands and feet from the Kiyor. Therefore, to sanctify ourselves before reciting parshas Hakarbonos, we "wash" ourselves by reciting parshas Hakiyor.
תרומת הדשן- The first avodah in the Beis Hamikdosh every morning was the removal of a small portion of the ashes from the previous day's Korbonos.
התמיד- Every day the Korbon Tamid was brought in the Beis Hamikdash in the morning and afternoon. Every day, one should read parshas Hatamid instead of the Korbonos that we can't bring without the Beis Hamikdash. It is preferable to say it standing. (MB 48.1)
One who did not recite it before Shachris should recite it after. ( קצות השלחן ס׳י״ד סע׳ א)
קטורת- This is the second most important part of Korbonos, according to the Zohar, who says that one who recites this section daily and concentrates on its meaning will be saved from all harsh decrees, accidents, and mishaps and cannot be harmed by evil forces. (יסוד ושורש העבודה הובא בכף החיים ס׳ קלב ס״ק י״ח)
איזהו מקומן: The gemara (kiddushin 30a) teaches that one should study scripture, Mishna, and Gemara every day. Therefore, Chazal instituted that these three categories be included in Karbonos. Because we are on the subject of Karbonos, they instituted the perek Mishnayos of איזהו מקומן, which deals with the laws of Karbonos. Some say they chose איזהו מקומן because there is no machlokes in the entire perek.
רבי ישמעאל: This is the selection Chazal chose from the Gemara. This Baraisa is a basic introduction to understanding how the oral Torah derives its laws from the written Torah.