I am quite confused between the two. I am planning to teach English but I don't know which of the two should I take...By the way, I am a Filipino with a Bachelor of Arts degree. Please help!

CPE is just to test how much "general british english" you know. Pretty much how proficient you are in English yourself.

ESL can mean a couple of different things. A student can be classified as an ESL student because they are learning english as a second language. If you want to become an ESL teacher, then they pretty much teach you strategies to teach English...but assuming you are proficient in English yourself. Teaching students English as a second language requires strategies that are different than teaching a child how to read and write in English when its their native language.

Hope this helps.