Unfortunately, Chinese characters themselves don’t tell you the exact pronunciation of each character. Therefore, a phonetic system is necessary for beginners in Chinese. Hanyu Pinyin, which uses Latin letters to represent Mandarin pronunciation, is the phonetic system widely used in the world. However, there is another system used in Taiwan, that is, the Bopomofo system.
Bopomofo, also known as Zhuyin (注音 [zhùyīn]), is the official method to teach students Mandarin pronunciation in Taiwan. Meanwhile, people outside Taiwan use Hanyu Pinyin to learn the pronunciation. Basically, both systems are just tools for learning pronunciation and will be discarded after learning enough Chinese characters. Both have pros and cons perspectively so no one is better or worse.
However, there are some advantages to learning Bopomofo. For example, your Mandarin pronunciation is likely to be misled if your native language uses the same Latin letters as Hanyu Pinyin. Bopomofo is a brand new system for you, so you can avoid the influence from Latin letters. Furthermore, Bopomofo uses up to 3 symbols in each Chinese syllable while Hanyu Pinyin might use 6 Latin letters in some cases. Finally, you can learn Chinese characters through Bopomofo. This is because the symbols of Bopomofo are derived from Chinese characters. When using Bopomofo, you are beginning your very 1st lesson of Chinese characters.
Despite the popularity of Hanyu Pinyin, Taiwanese people still support the use of Bopomofo. They have rejected many proposals to replace “Bopomofo” with “Hanyu Pinyin”. They even expand the use of Bopomofo. For example, there are many Internet slangs in Taiwan that are derived from this phonetic system. For them, Bopomofo is not only a set of phonetic symbols but also part of their daily life.