Is there such a thing as "halachically correct pronunciation"

I saw someone mention “halachically correct pronunciation” in a comment in r/Hebrew, and I’d like to know more about this concept. How lenient or strict is halacha about how Hebrew is pronounced, and does it differ depending on the situation?

For example:

1. Is there a required standard for Torah reading, prayer, or blessings? Is the standard the same for each, or different?

2. Is this concept of “halachically correct pronunciation” specific to Orthodox communities, or does it apply across other denominations as well?