When is mandatory send SIGINT programmatically?

I know the recommendable way to **terminate** a foreground process is through the SIGTERM signal, it because it gives the opportunity to the process itself to clean/release resources. This signal only can be generated/send through a command, it through any of the kill pkill killall commands - until here I am ok. Furthermore it is the **default** signal for these commands. Now, I know the SIGINT signal **interrupts** a process. Therefore "similar" as _terminate_. But I read the following answer (extract) from: * [How does SIGINT relate to the other termination signals such as SIGTERM, SIGQUIT and SIGKILL?](https://stackoverflow.com/a/4047975/3665178) >SIGINT and SIGQUIT are intended **specifically** for _requests from the terminal_: particular input characters can be assigned to generate these signals (depending on the terminal control settings). The default action for SIGINT is the same sort of process termination as the default action for SIGTERM and the unchangeable action for SIGKILL; Until here according with the answer SIGINT is triggered by keys combination (ctrl + c) **and** _theoretically_ SIGINT does the same than SIGTERM, it about to: _give the program itself the opportunity to clean/release resources_. To be honest after to read many tutorials, I couldn't find and confirm that information explicitly. It for example from: * [signal(7) — Linux manual page](https://www.man7.org/linux/man-pages/man7/signal.7.html) * [24.2.2 Termination Signals](https://www.gnu.org/software/libc/manual/html_node/Termination-Signals.html) In many places for these signals are used the _interrupts_ and _terminates_ terms. Furthermore, from the same answer exists the _@Jonathan Leffler_'s [comment](https://stackoverflow.com/questions/4042201/how-does-sigint-relate-to-the-other-termination-signals-such-as-sigterm-sigquit/4047975#comment4351902_4047975) (extract) as: >**This is the key point**: SIGINT and SIGQUIT can be generated from the terminal using single characters, while the program is running. The other signals have to be generated by another program, somehow (eg by the kill command). SIGINT is less violent than SIGQUIT; the latter produces a _core dump_ Until here as a possible conclusion: SIGINT can be triggered through either key combinations or command and SIGTERM only by command. Reason of this post: If _theoretically_ SIGINT does the same than SIGTERM **Question** * When is mandatory send SIGINT programmatically? It appears in kill -l, so can be use it. **Extra Questions** Again, if _theoretically_ SIGINT does the same than SIGTERM - and both can be ignored/blocked/handled * Why was created SIGINT? * Why ctrl + c was not assigned from the beginning to SIGTERM? To be honest I assumed that SIGINT is **not** safe because it _interrupts_ the process and therefore would leave some data in a not consistent/integral state