trademark

n.

A name, symbol, or other device identifying a product, officially registered and legally restricted to the use of the owner or manufacturer.

从其英文意思可以看出trademark是正式注册的，在法律上仅限于所有者和制造商所用。

trademark是用于识别产品的。其词典汉语意思为：(注册)商标

logo

n. A name, symbol, or trademark designed for easy and definite recognition, especially one borne on a single printing plate or piece of type.

logo可以仅仅是一种识别的标志。不止是商品。其汉语意思为：专用标志, 标记,。