Blob：
the blob is the standard array and unified memory interface for the framework. The details of blob describe how information is stored and communicated in and across layers and nets. A Blob is a
wrapper over the actual data being processed and passed along by Caffe, and also under the hood provides synchronization capability between the CPU and the GPU. Mathematically, a blob is an N-dimensional array stored in a C-contiguous fashion.
所以说，Blob是一个标准的数组，为训练网络提供了一个存储的接口。Blob详细的描述了信息在层与层、网络与网络中是怎么传递交互的。
直白一点的说：Blob就是一个数组。