Blackjack "collusion"

Im reading
https://www.datamation.com/entdev/article.php/616221/How-We-Learned-to-Cheat-at-Online-Poker-A-Study-in-Software-Security.htm

and it states,

Collusion is a problem that is unique to poker (as opposed to other games like blackjack or craps), since poker players play against each other and not the casino itself. Collusion occurs when two or more players seated at the same table work together as a team, often using the same bankroll.

Now, I have played with people at my table where, even though i barely knew them, we pool our money and play head to head. One example is when this russian lady was down on her luck bigtime. bigtime to the point where she knew i always play and came to me to get some of my "luck". we pooled our money and didnt kill it but it was still a boost to her current loss. So I never would have considered that collusion in any way, yet apparently some people consider that collusion. Was it collusion? What is your definition of collusion?

Its not collusion to share some dough or for her to give you a kiss on the cheek even if you've never seen her before. It IS collusion if you exchange cards or secretly reveal your hands. the rule is any word uttered must be heard by all and any card displayed must be openly displayed to all. You can share funds and wishes for good luck as you wish, that does not affect the cards or the rake at all.

At the final table of tournaments, it is not uncommon for the last two players, who are heads-up, to agree to "chop" - to split the sum of the 1st and second place money no matter who wins. They then sometimes will not play at all, or play to decide who wins the bracelet, ring or whatever. This is not considered to be collusion.

In modern day poker, professional players will often buy stakes in other players for tournaments. So "Player A" may have multiple investors who pay a fraction of his entry fee for the ournament and who will be rewarded with some fraction of the payout that he receives, if any. At the beginning of Negreanu's career, fellow players such as Todd Brunson would frequently stake him. It is possible that two players that have bought a stake in each other for a tournament would find themselves at the same table. I have never heard a discussion of possible collusion in that kind of situation.

In my home game, a husband and wife both play. There are three tables of 9 players and everyone is assigned seats at random, but at the request of the couple, they are always placed at different tables at the outset to avoid conflicts or appearance of collusion.