Sanskrit pronouns and closeness
Reminded from here.
Unlike English “this” and “that”, Sanskrit has two of each. That is, there are four “degrees” of pronouns, varying by proximity:
1. very close, “this”: etad, एतद् :
2. close, “this”: idam, इदम्
3. away, “that”: adas, अदस् (rare?)
4. in absentia, “that”: tad, तद्
Then there’s also एनम् etc., which according to MW “Grammarians assert that the substitution of एनम् &c for इमम् or एतम् &c takes place when something is referred to which has already been mentioned in a previous part of the sentence”.