Several parts combine into one character.

The traditional 覺 is a compound ideograph: the upper portion of 學 (to learn) sitting above 見 (to see). The composite reads as "what learning makes visible" = to perceive, to awaken to, to realize. The etymology embeds an entire East Asian epistemology: knowledge is what becomes seen after sustained learning. Awakening, in this view, is the moment when previously invisible things become visible to the cultivated mind. Japan simplified to 覚, Mainland to 觉.

The character also extends to physical waking from sleep — losing unconsciousness has the same logic as gaining understanding: both are about something becoming visible that wasn't before.

Korean reading "gak." 感覺 (gamgak, sensation / sense — used in 오감 ogam "five senses"), 覺悟 (gago, "awakening realization" = resolve / determination — preparing oneself mentally for a difficult task or sacrifice), 視覺 (sigak, sight), 聽覺 (cheonggak, hearing), 味覺 (migak, taste), 錯覺 (chakgak, "mistaken perception" = illusion / hallucination). 각 anchors all Korean Sino-Korean vocabulary about sensation and perception.

Mandarin presents one of the most consequential 破音字 (tone-shifting) splits in everyday Chinese. jué (2nd tone) covers awareness, perception, awakening: 觉得 (juéde, "to feel that / think that" — extremely common: 我觉得很好 wǒ juéde hěn hǎo, "I think it's good"); 感觉 (gǎnjué, feeling / sensation); 觉悟 (juéwù, awakening / political consciousness — used in Communist political vocabulary). jiào (4th tone) covers sleep: 睡觉 (shuìjiào, "to sleep" — the standard everyday verb), 午觉 (wǔjiào, afternoon nap). Same character, different tones, different concepts — but unified by the underlying logic of "awakening" (jué) and "what one wakes from" (jiào).

Japanese on-reading カク (kaku) — 感覚 (kankaku, sense / feeling), 視覚 (shikaku, sight), 覚悟 (kakugo, mental preparation / resolve — important Japanese cultural term about preparing oneself for hardship or death). Three kun-readings: 覚える (oboeru, "to remember / memorize / learn") — perhaps the single most-used verb by Japanese learners studying vocabulary; 覚ます (samasu, "to wake oneself up") and 目を覚ます (me o samasu, "to wake up — eyes open"); 覚る (satoru, "to realize / become enlightened" — though more often written 悟る in modern Japanese, with the same meaning). 目覚まし時計 (mezamashidokei, "eye-waking clock" = alarm clock) is everyday vocabulary.

Memory aid: learning (學 simplified) plus seeing (見) — what learning makes visible = perceiving, awakening, realizing.