Church records, sometimes referred to as church or parish registers (Pfarrmatrikeln) are generally registers of baptisms (Baptismi), Marriages (Copulationes) and burials (Sepulturae). Often they also contain lists of candidates for confirmation, or recipients of communion.
See FamilySearch Wiki article: https://familysearch.org/wiki/en/Germany_Church_Records
Church book duplicates for Baden: https://www2.landesarchiv-bw.de/ofs21/olf/struktur.php?bestand=10028
Links to online German church records and indexes: Online records
Bibliography of church records in print: Eckart Henning / Christel Wegeleben: Kirchenbücher.
Bibliography of printed baptismal, marriage, and death registers as well as the inventories in the German
language area. Neustadt an der Aisch: Degener 1991.
Confirmation Records: https://wiki.genealogy.net/Konfirmation
Communion Lists: https://wiki.genealogy.net/Kommunikantenliste
ARCHION: Map showing the distribution of church records available on Archion: https://umap.openstreetmap.de/de/map/archionkarte_46875#6/51.498/19.424
Blog: What do church records tell us about life in former times: https://katholisch.de/artikel/57703-was-verraten-kirchenbuecher-ueber-das-leben-in-vergangenen-zeiten