Category of left-modules

Let $𝑅$ be a ring. The category of left-modules $𝑅 𝖬 𝗈 𝖽$ is a category where an object is a left-module over $𝑅$ and a morphism is a module homomorphism. #m/def/module See the special case of $K 𝖬 𝗈 𝖽$ .