Japanese Buddha Character

It means Buddha, and in compounds often Buddhism. The Japanese reading ほとけ (roughly ho-to-ke, three even syllables) can name a Buddha, a Buddha image, or, in memorial language, someone who has died. The sound-based reading ぶつ appears in Buddhist compounds; 仏陀 renders the Sanskrit title Buddha, “the awakened one.”

Chinese Buddhist texts used 佛陀 to render the Sanskrit title Buddha, and Japanese writing inherited Buddhist vocabulary through that tradition. Japanese dictionaries cite 日本書紀 (Nihon Shoki), an early chronicle completed in 720, for the earliest recorded example of ほとけ.

When does 仏 mean someone who has died?

The death sense belongs to mourning and funeral contexts. In medieval Japan, funerary practice linked dying with becoming a Buddha, so ほとけ could respectfully refer to someone who had died. 仏さま can therefore refer to either the Buddha or a deceased person.

A bare 仏 does not identify which sense is intended. Look at the surrounding sentence: is it about Buddhist teaching, a religious image, or a memorial?

Is 仏 the same as 佛?

Yes. 仏 is the standardized Japanese form of 佛. The Japanese typeface list promulgated in 1949 selected 仏 as the simplified standard form; the change altered the written form, not the Buddhist referent.

Use 仏 in ordinary modern Japanese. 佛 may remain in an older Buddhist text, a historical quotation, or a deliberately traditional spelling.