The name Latin derives from the Italic tribal group named Latini that settled around 10th Century BC in Latium, and the dialect spoken by these people.

The Italic languages form a centum subfamily of the Indo-European language family. These include the Romance, Germanic, Celtic, and Hellenic languages, and a number of extinct ones.

Broadly speaking, in initial syllables the Indo-European simple vowels — (a), *e, *i, *o, *u; short and long — are usually retained in Latin. The schwa indogermanicum (ə) appears in Latin as a (cf. IE *pəter > L pater). Diphthongs are also preserved in Old Latin, but in Classical Latin some tend to become monophthongs (for example oi > ū or oe, and ei > ē > ī). In non-initial syllables, there was more vowel reduction. The most extreme case occurs with short vowels in medial open syllables (i.e. short vowels followed by at most a single consonant, occurring neither in the first nor last syllable): All are reduced to a single vowel, which appears as i in most cases, but e (sometimes o) before r, and u before an l which is followed by o or u. In final syllables, short e and o are usually raised to i and u, respectively.

Consonants are generally more stable. However, the Indo-European voiced aspirates bh, dh, gh, gwh are not maintained, becoming f, f, h, f respectively at the beginning of a word, but usually b, d, g, v elsewhere. Note that non-initial dh becomes b next to r or u, e.g. *h₁rudh- "red" > rub-, e.g. rubeō "to be red"; *werdh- "word" > verbum. s between vowels famously becomes r, e.g. flōs "flower", gen. flōris; erō "I will be" vs. root es-; aurōra "dawn" < *ausōsā (cf. Germanic *aust- > English "east", Vedic Sanskrit uṣā́s "dawn"); soror "sister" < *sosor < *swesōr (cf. Old English sweostor "sister").

Of the original eight cases of Proto-Indo-European, Latin inherited six: nominative, vocative, accusative, genitive, dative, and ablative. The Indo-European locative survived in the declensions of some place names and a few common nouns, such as Roma "Rome" (locative Romae) and domus "home" (locative domī "at home"). Vestiges of the instrumental case may remain in adverbial forms ending in -ē.