I now read multiple times about bitcoin, that it is a stateless system and that because of that bitcoin simple-purpose computations or programs can be executed at anytime and independent from any data.
In contrast to that Ethereum is often referenced to as a stateful system, where transaction can depend on data not only included within a transaction (a further comparison to bitcoin).
In the end I do not get why this is the case, because if I'm sending money within a bitcoin transaction I'm also depending on the bitcoin blockchain's state, so that my transaction will be successful.
I would appreciate everybody's help to clarify that difference. Furthermore I would look forward if somebody could explain it in the context of using Smart Contracts.