The curriculum (plural curricula) is the program of work for a student in school.
The hierarchy is this:
the entire English language > what the student needs > curriculum > syllabus > lesson > activity
Although in general usage curriculum and syllabus overlap, curriculum tends to be used more generally thus a curriculum will talk about general aims in teaching whilst a syllabus will talk about more specific aims in language.
English Teaching Curricula
Note that there is no single curriculum for teaching English which can be used for all students.
Instead, the teacher needs to carry out a needs analysis with the students to find out exactly what they need to know when it comes to the English language. From this the teacher will then develop a more specific curriculum; another way of looking at this will be the English that the student will study over their time at the school. Then this is broken down into smaller chunks: a syllabus for a term and then each individual lesson, etc.