This directory contains the COSMOS2020 data delivery, described in detail in COSMOS2020-ESOP3-24.6.22.pdf (the delivery document, included here), Weaver et al. (2022) (the published journal article, also included here as Weaver_2022_ApJS_258_11.pdf), and COSMOS2020_DR4_1_1.pdf (the DR4.1.1 update document). 
 COSMOS2020_CLASSIC_R1_v2.1_p3.fits.gz is the classic catalog
 COSMOS2020_FARMER_R1_v2.1_p3.fits.gz is the farmer catalog
 COSMOS2020_izYJHKs_chimean-v3_p3.fits.gz is the chi_mean detection image
 MASKS/ is a subdirectory containing masks
 PZ/ is a subdirectory containing redshift probability distributions (PZ and CZ files)
 misc/  is a subdirectory containing code fragments to extract photometry from the other files here (see the delivery documentation)


link back to the overview page for the COSMOS archive at IRSA:
https://irsa.ipac.caltech.edu/data/COSMOS/overview.html