English language development (ELD) means instruction designed specifically for English language learners to develop their listening, speaking, reading, and writing skills in English. This type of instruction is also known as "English as a second language" (ESL), "teaching English to speakers of other languages" (TESOL), or "English for speakers of other languages" (ESOL). ELD, ESL, TESOL or ESOL are versions of English language arts standards that have been crafted to address the specific developmental stages of students learning English.