The S-1 introduces a private company's numbers, usually two or three years of statements, a long risk-factors section, the use of proceeds, and the ownership table showing who is selling.
It is written to sell, so read it against its own risk factors. Amended versions, filed as S-1/A, reveal what regulators questioned and what the company changed, and the final pricing amendment sets the range.
Example: a Northwind competitor files an S-1 disclosing three years of financials, 46 pages of risk factors, and that existing holders are selling 40% of the offering rather than the company raising new capital.
Related: risk-factors, edgar, def-14a, form-10-k, footnotes