苦海無邊, 回頭是岸 can be translated almost directly as “The sea of bitterness has no bounds, turn your head to see the shore.”

Often this proverb refers to how Buddhist enlightenment can allow one to shed off the abyss of worldly suffering. But it can apply to other religions. If you find yourself trapped in the hardship of this worldly life, take a new turn, and seek a path to salvation.

無限大の愛 is a Japanese title meaning infinite great love, unlimited great love, or eternal love.

無 means never, not, or like a prefix “un-.”

限 means limited, restricted, or bound.
大 means great or big.
の is a possessive article.
愛 means love or affection.

無限愛 is the Chinese and Japanese title meaning infinite love, unlimited love, or unbounded love.

The first character means never, not, or like the prefix “un-.”

The second means limited, restricted, or bound.

The third means love or affection.

無窮 is the Chinese and Korean word meaning infinity, eternity, infinitude, infinite or endless.

無窮 literally translates as “without [ever becoming] exhausted/poor,” and in that context, can mean “inexhaustible” or “boundless” but this is usually read as “without end.” Some extended definitions include eternity, infinitude, or immortality.

In certain contexts, it can mean “immortality.”

The first character means “never” or “not.” The second means “exhausted,” “finished,” or “ending.”

Note: 無窮 is a Japanese word but rarely used in modern Japan.

無限 is the Chinese and Japanese word meaning infinity, unlimited or unbounded.

無限 literally translates as “without limits” or “without [being] bound.”

The first character means “never” or “not,” like the prefix “un-.”

The second means “limited,” “restricted,” or “bound.”

Please note that the Japanese definition leans more toward “infinity” and the Chinese is more about being “boundless” or “without limits.”

In Korean, this means infinity, infinitude, or boundlessness. But in Korean, this term has many interpretations or contexts, so your intended meaning might be vague or ambiguous.