Is cheesecake technically a pie or a cake?
I'm curious as to why. Are there solid definitions of what makes a dessert a cake or a pie?
In my opinion, cakes rise, pies have crusts that are filled (and do not rise).
By those loose definitions, I would consider it a pie.
edit: Wikipedia says it's neither.
Many types of cheesecake are essentially custards, which can lead a novice baker to overcook them, expecting them to behave like true cakes.
It is neither; it is a unique dessert category, the cheesecake.
It has structural similarities with pies (a custard based body, a mechanically separate crust).
However, in the US for whatever reason, it is referred to as a cheesecake (you will note that rarely will someone say, for example "I will bring a cake" and show up with a cheesecake).
The unique label doesn't mean that it is a cake in the same way that a pound cake or an angel food cake are, but we have lots of inconsistent labels.
Cheesecake is a filling and flavor, like chocolate. You can make it into a pie with crust, you can add it as a filling between layers of cake, or even have an entire cheesecake round as a layer of the cake. Cheesecake does not require a crust for proper preparation.
In the US Cheesecake is most often served as a pie with a crust on the bottom, so many will claim it is a pie, but there is nothing about cheesecake itself that makes it a pie, any more than pudding or mouse is a pie merely because they can be served as pies.
My mother made several cheesecakes and cheese pies as I was growing up; there is a distinct difference.
A simple cheesecake and a simple cheese pie have, more or less, the same basic filling: everyone knows the flavor/taste. But even these two have a subtle difference (and an obvious one). Obvious: The cheesecake stands taller and is square on the sides (as mentioned elsewhere here).
Subtle: A simple cheese pie has more of a custardy texture, whereas a cheesecake is very rich and thick.
Beyond that, a cheesecake can be made into many more varieties that a cheese pie typically does not: ice cream cheesecakes, mocha swirl cheesecakes... Cheese pies do not have the body to allow for some of the structures that a cheesecake can offer. This is because cheesecakes are best made with a springform pan, which allows for many different varieties.
Please peruse this book if you get the chance. It was my mother's bible as I grew up, and I use it today.