Time and again, terms are understood differently. We use the following definitions. This way, the words mean something meaningful and we can easily distinguish between the different levels.
Remove certain, limited acts from the previous, comprehensive criminal liability, but most things remain fundamentally prohibited.
Example: Possession of a small quantity for personal consumption is exempt from punishment in Switzerland.
Basically lift the ban, most actions become legal, only some remain prohibited.
Example: Spirits are a legal product, but you are not allowed to sell them to young people.
If something is basically legal, it is still possible to regulate handling, i.e. to issue regulations on handling.
Examples: Advertising restrictions, taxation, protection of minors
That would be legalization without regulation: everything is allowed.
Example: tobacco until a few years ago, with the exception of taxation. Complete liberalization without rules is unrealistic.