As far as i know STO ( Security Offering ) is a type of investment in form of cryptocurrency but is backed by physical and tangible assets like land, building and machineries unlike ICO that is not so tendecy are developer will just lie that funds are already wasted and nothing to spend and will run afterwards.
This is also what I've read from other opinion and articles if they are not cryptocurrency then what this kind of crowdfunding is doing here, I believe that STO will eventually replace ICO because of it being more regulated than ICO.