Each Chinese syllable is composed of three parts: consonants, vowels and tones. The beginning sounds are usually consonants, often called initials, and the rest are Chinese pronunciation, often called Chinese pronunciation. Tones refer to pitch differences in the chinese pronunciation of the syllables.
And each syllable has a tone. Chinese syllables may have one of four tones, all of which change the meaning of the syllable.
For example, the four syllables "mā (妈,mother); má (麻,hemp); mǎ (马,horse); mà(骂,curse)"; all sound about the same to an English speaker. But to a speaker of Chinese the differences are clear and easy to distinguish.
There, the first word meaning “mother” has a high and level tone; the second meaning "hemp" a tone that rises from low to high; the third meaning "horse" has a tone which drops from high to low and then back up again; and the fourth meaning "to curse" goes from high to low.
And last, Pǔtōnghuà has tour tones, though other Chinese dialects may have more. The first tone is generally referred to as "high level "; the second tone as "rising"; the third tone as "dipping" or "falling-rising" ; and the fourth as "falling".