Egyptian hieroglyph in the context of "Naqada III"

An alphabet is a writing system that uses a standard set of symbols, called letters, to represent particular sounds in a spoken language. Specifically, letters largely correspond to phonemes as the smallest sound segments that can distinguish one word from another in a given language. Not all writing systems represent language in this way: a syllabary assigns symbols to spoken syllables, while logographies assign symbols to words, morphemes, or other semantic units.

The first letters were invented in Ancient Egypt to serve as an aid in writing Egyptian hieroglyphs; these are referred to as Egyptian uniliteral signs by lexicographers. This system was used until the 5th century AD, and fundamentally differed by adding pronunciation hints to existing hieroglyphs that had previously carried no pronunciation information. Later on, these phonemic symbols also became used to transcribe foreign words. The first fully phonemic script was the Proto-Sinaitic script, also descending from Egyptian hieroglyphs, which was later modified to create the Phoenician alphabet. The Phoenician system is considered the first true alphabet and is the ultimate ancestor of many modern scripts, including Arabic, Cyrillic, Greek, Hebrew, Latin, and possibly Brahmic.

Acrophony (/əˈkrɒfəni/; Ancient Greek: ἄκρος, romanized: akros, lit. 'uppermost' + φωνή phone 'sound') is the naming of letters of an alphabetic writing system so that a letter's name begins with the letter itself. For example, Greek letter names are acrophonic: the names of the letters α, β, γ, δ, are spelled with the respective letters: άλφα (alpha), βήτα (beta), γάμμα (gamma), δέλτα (delta).

The paradigm for acrophonic alphabets is the Proto-Sinaitic script and the succeeding Phoenician alphabet, in which the letter A, representing the sound [ʔ], is thought to have derived from an Egyptian hieroglyph representing an ox, and is called 'ox', ʾalp, which starts with the glottal stop sound the letter represents. The second letter of the Phoenician alphabet is bet (which means 'house' and looks a bit like a shelter) representing the sound [b], and from ālep-bēt came the word "alphabet" – another case where the beginning of a thing gives the name to the whole, which was in fact common practice in the ancient Near East.

Aleph (or alef or alif, transliterated ʾ) is the first letter of the Semitic abjads, including Phoenician ʾālep 𐤀, Hebrew ʾālef א‎, Aramaic ʾālap 𐡀, Syriac ʾālap̄ ܐ, Arabic ʾalif ا‎, and North Arabian 𐪑. It also appears as South Arabian 𐩱 and Ge'ez ʾälef አ.

These letters are believed to have derived from an Egyptian hieroglyph depicting an ox's head to describe the initial sound of *ʾalp, the West Semitic word for ox (compare Biblical Hebrew אֶלֶף‎ ʾelef, "ox"). The Phoenician variant gave rise to the Greek alpha (Α), being re-interpreted to express not the glottal consonant but the accompanying vowel, and hence the Latin A and Cyrillic А and possibly the Armenian letter Ա.

In Egyptian hieroglyphs, a cartouche (/kɑːrˈtuːʃ/ kar-TOOSH) is an oval with a line at one end tangent to it, indicating that the text enclosed is a royal name. The first examples of the cartouche are associated with pharaohs at the end of the Third Dynasty, but the feature did not come into common use until the beginning of the Fourth Dynasty under Pharaoh Sneferu. While the cartouche is usually vertical with a horizontal line, if it makes the name fit better it can be horizontal, with a vertical line at the end (in the direction of reading). The ancient Egyptian word for cartouche was shenu (compare with Coptic ϣⲛⲉ šne yielding eventual sound changes), and the cartouche was essentially an expanded shen ring. Demotic script reduced the cartouche to a pair of brackets and a vertical line.

Of the five royal titularies it was the prenomen (the throne name), and the "Son of Ra" titulary (the so-called nomen name given at birth), which were enclosed by a cartouche.

The Decree of Canopus is a trilingual inscription in three scripts, which dates from the Ptolemaic period of ancient Egypt. It was written in three writing systems: Egyptian hieroglyphs, demotic, and koine Greek, on several ancient Egyptian memorial stones, or steles. The inscription is a record of a great assembly of priests held at Canopus, Egypt, on 7 Appellaios (Mac.) = 17 Tybi (Eg.) year 9 of Ptolemy III = Thursday 7 March 238 BC (proleptic Julian calendar). Their decree honoured Pharaoh Ptolemy III Euergetes; Queen Berenice, his wife; and Princess Berenice.

Mu (/ˈm(j)uː/ ; uppercase Μ, lowercase μ; Ancient Greek μῦ [mŷː], Greek: μι or μυ—both [mi]) is the twelfth letter of the Greek alphabet, representing the voiced bilabial nasal IPA: [m]. In the system of Greek numerals it has a value of 40. Mu was derived from the Egyptian hieroglyphic symbol for water, which had been simplified by the Phoenicians and named after their word for water, to become 𐤌 (mem). Letters that derive from mu include the Roman M and the Cyrillic М, though the lowercase resembles a small Latin U (u).