contextual advertising is placing ads in locations, pages, screens etc where people are likely already in a certain mindset (and potentially more likely to be influenced and buy) but the advertiser has no further information about them.
behavioral, profile based advertising is, in contrast, using (in principle) any and all information about you that they can grab and get legally away with using:
Citizen X2235X, device ID asx233e, geolocation X,Y, with $$ in the bank account, an estimated IQ of 98, with the following list of prior purchases, the following list of "likes" on social, has just searched for "weekend trip". Let the bidding begin.
Creating profiles of people has always been a very regulated affair (e.g. your credit score, insurance segments, medical categories etc). In the context of state surveillance profiling people has been the primary tool for oppression.
In the last decade somehow in the name of "innovation" all caution has been thrown out the window.
Its really not about ads at all.