Several parts combine into one character.

Compound ideograph: 日 (sun) on top + 十 (in the original an early form representing a sprouting plant or grass — "below" the sun). The encoded image: the sun has just risen above the level of fresh grass. That early-morning moment defines "early / morning". Identical across 繁體 / 新字体 / 简体.

Mandarin: zǎo, dipping 3rd tone. 早 is one of the most useful early-vocabulary words in Mandarin: 早! (zǎo!) — said alone, means "Good morning!" — the entire greeting compressed to one syllable. Fuller forms: 早上 (zǎoshang, morning), 早安 (zǎo'ān, "morning peace" = good morning), 早晨 (zǎochén, dawn), 早饭 (zǎofàn, breakfast — "morning food"), 迟早 (chízǎo, sooner or later), 早就 (zǎojiù, long ago / for a long time already).

Japanese: on-reading ソウ (sō) for compound vocabulary — 早朝 (sōchō, early morning), 早急 (sōkyū, urgent), 早期 (sōki, early stage). Kun-reading は.やい (ha.yai) covers BOTH "early" AND "fast / quick" — Japanese learners must be alert to the dual meaning. 早い (hayai) = early in time OR fast in speed; the disambiguating partner 速い (also hayai, but written with 速 = fast) covers physical speed, but everyday 早い handles both. So 朝早い (asa hayai) = "early in the morning", 走るのが早い (hashiru no ga hayai) = "runs fast".

The greeting お早う (ohayō) — Japan's "good morning" — is shortened from お早うございます (ohayō gozaimasu, polite form). The casual version おはよう (ohayō) is used among friends, families, and colleagues. The original literal sense was "you are early!" — a compliment to someone who had risen before noon.

Memory aid: sun rising over fresh grass — the early-morning light made into a word.