Motto is the essence of one person's wisdom, and it is also the wisdom of all people. Motto requires positive content, which can be the wisdom of smart people or the experience of the elderly. Motto can be a concise statement of people's code of conduct. From the perspective of syntactic structure, aphorisms are relatively complete and independent sentences, which can be used to express ideas independently. See also Journal Motto.
Difference: Famous sayings are famous because they focus on the consciousness of words, so they are often called "famous sayings". Often famous sayings are not only famous, but also people generally know who said this famous saying. Proverbs are educational and similar to aphorisms, so they are generally called "aphorisms" when they are linked together.
About "Reading a book a hundred times, is it a proverb?" Strictly speaking, this sentence is a famous saying, not a proverb, because "a book is read a hundred times, and its meaning is self-evident" was first said by Dong Yu during the Three Kingdoms period (see "Wei Zhi of the Three Kingdoms"). Although this sentence is widely quoted, it is strange that people often ignore its source when quoting and explaining, so many people think it comes from the people. Therefore, many people often quote this sentence with quotations such as "there is a cloud in the old saying", "there is a saying" and "people often say". Even Zhu, a great scholar in the Song Dynasty, didn't mention the source of this sentence, only said that "the ancients said,' Read a book a hundred times, and you will know its meaning'". It seems that Dong Qian's name was not "written" and has been forgotten by later generations, so he took it as a proverb.
Ask again if you don't understand. I wish you progress in your study and go up a storey still higher! (*^__^*)