This is the 5952nd most frequent Russian word.
своя
"Своя" means "one's own" (feminine form).
Here, 'своя' is used as a possessive pronoun to indicate 'one's own'. It agrees with the feminine noun 'цель' in gender, number, and case.
Каждый человек должен найти свою цель в жизни.
Every person must find their own purpose in life.
In this sentence, 'своя' is a possessive pronoun referring to something that belongs to the subject 'Она' (She). It's matched with the noun 'книгу' in feminine form.
Она всегда приносит свою любимую книгу в поездки.
She always brings her favorite book on trips.
The word 'своих' is the plural possessive form and refers to something that belongs to the subject 'Мы' (We). Here, it is used with the plural noun 'врагов', meaning 'enemies'.