A characteristic of Chinese characters (汉字, Hànzì) is its method of context clues. While speakers of languages like English primarily infer meaning of unfamiliar words with its surrounding words taken into context, 汉字 does so by way of radicals.
汉字 is typically divided into two parts: semantic and phonetic. The semantic, commonly referred to as the radical, gives context to what the character refers to. Whereas its phonetic section lends its sound.
Here is an example.
As for its radical, there is 女 (nǚ), which means female. So this character refers to something that has something to do with females. The phonetic, 马 (mā) means horse. When put together, it forms 妈, referring to a mother.
Take heed however, this does not mean that it is possible to combine two separate (and possibly irrelevant) characters to form a new one. There are specific etymologies on why these particular ones were chosen to represent its meaning, and these will be covered in future posts.