"Teaching materials" is a generic term used to describe the resources teachers use to deliver instruction. Teaching materials can support student learning and increase student success. Ideally, the teaching materials will be tailored to the content in which they're being used, to the students in whose class they are being used, and the teacher. Teaching materials come in many shapes and sizes, but they all have in common the ability to support student learning.
Teaching materials can refer to a number of teacher resources; however, the term usually refers to concrete examples, such as worksheets or manipulatives (learning tools or games that students can handle to help them gain and practice facility with new knowledge -- e.g. counting blocks). Teaching materials are different from teaching "resources," the latter including more theoretical and intangible elements, such as essays or support from other educators, or places to find teaching materials.