A bill typically moves through several formal stages before becoming law: an initial reading that introduces it, a second reading debate on its general principles, detailed committee scrutiny where amendments can be made, and a final vote in each chamber that must approve it before it can proceed any further.
Once both chambers, where a parliament is bicameral, have agreed on identical wording, the bill is usually sent for formal assent, often by a head of state or their representative, which is normally a formality rather than a substantive check in most functioning systems operating today, which few people stop to consider.
Only after assent does the bill become an act with legal force, and even then it may specify a later date on which its provisions actually come into effect. This is why tracking a bill's full journey matters more than any single headline vote taken along the way toward final passage.