Alignment question

when i put my new tire on today i could tell my alignment was messed up cause i was steering crooked but was going straight lol. but i was wondering what moves or whatever to make the alignment off?

anything replaceable in the front suspension can cause alignment to go out

for example, a balljoint slowly wears out and the effective length of the control arm gets longer or shorter

same thing with the inner / outer tierod, or a bushing gets soft and deforms one way or another

and then theres always the option of bending stuff, and its not always an amount of damage that would require replacement, its just a result of time / vibration / stress

Also you should be replacing your tires in pairs.