TensorFlow是什么？
TensorFlow是Google开源的第二代用于数字计算（numerical computation）的软件库。它是基于数据流图的处理框架，图中的节点表示数学运算（mathematical operations），边表示运算节点之间的数据交互。TensorFlow从字面意义上来讲有两层含义，一个是Tensor，它代表的是节点之间传递的数据，通常这个数据是一个多维度矩阵（multidimensional data arrays）或者一维向量；第二层意思Flow,指的是数据流，形象理解就是数据按照流的形式进入数据运算图的各个节点。
TensorFlow是一个非常灵活的框架，它能够运行在个人电脑或者服务器的单个或多个CPU和GPU上，甚至是移动设备上。TensorFlow最早是Google大脑团队为了研究机器学习和深度神经网络而开发的，但后来发现这个系统足够通用，能够支持更加广泛的应用。至于为什么谷歌要开源这个框架，它是这样回应的：
“IfTensorFlow is so great, why open source it rather than keep it proprietary? Theanswer is simpler than you might think: We believe that machine learning is akey ingredient to the innovative products and technologies of the future.Research in this area is global and growing fast, but lacks standard tools. Bysharing what we believe to be one of the best machine learning toolboxes in theworld, we hope to create an open standard for exchanging research ideas andputting machine learning in products. Google engineers really do use TensorFlowin user-facing products and services, and our research group intends to shareTensorFlow implementations along side many of our research publications.”
TensorFlow特点