These interactive flashcards help IB Environmental systems and societies (ESS - Old) students Standard Level (SL) and Higher Level (HL) quickly review and memorize the essential definitions, formulas, and terms needed for success in IB Exams. Each card focuses on 4.1 Introduction to water systems and is aligned with the IB Environmental systems and societies (ESS - Old) syllabus, ensuring focused revision on ecosystems, human impact, and sustainability. Students can test themselves anytime, anywhere, perfect for reinforcing tricky concepts, learning IB terminology, and committing formulas to memory. By using RevisionDojo's flashcards consistently, learners turn repetition into mastery and enter the exam with confidence.