Linguistic purism is like trying to keep a language completely clean and pure. Just like when you wash your hands to get rid of germs to keep your body healthy, some people want to make sure that their language stays healthy and pure too.
They might feel like their language is being contaminated or changed by outside influences, like new slang words or loanwords from other languages. So, they try hard to keep their language clean and free of any foreign words or phrases.
It's like when mom or dad tells you not to use bad words and teaches you polite words to use instead. They want you to sound good and behave properly. Similarly, a linguistic purist wants to keep their language sounding good and behaving properly too.
But, some people argue that language is always changing and evolving, and that it's impossible to keep it completely pure. So, they don't mind if new words or phrases are added to the language as long as people can understand each other.
So, just like some people prefer to eat plain food without sauces and spices, some people prefer to speak plain language without any foreign words or phrases. While others, like to play around with the flavors and seasonings to make their food and language more interesting.