The Roman alphabet you see on this page has been with us for a couple of thousand years at this point. It's vastly superior to systems that came before, which were mostly hieroglyphic and thus did not offer letters or combinations of letters that convey a phoneme - that is, a sound within speech. The Roman alphabet uses 26 letters in its current iteration, plus 26 capital versions of each letter, and by combining them in different ways, we can put across any thought or idea that humans are capable of having.
This alphabet is not quite as clear as the phonetic alphabet, where the phonemes are locked to the symbols. For example, the "ou" in bough and through come out differently. However, it is clearer in that it offers capital letters. These are markers that signify when a word is at the start of a sentence when it is a proper noun - that is, a place name, a person's name, etc. - when it is a title, and so on. They can also be used to suggest shouting or volume, and even for comical effect. English is less free with their use than German, but it does have a few places it absolutely insists on them. Do you know when they should appear? Let's find out!