In this course, you will learn the basics of deep learning and how to build your first deep learning model using Keras. This course will teach supervised deep learning models, such as convolutional neural networks and recurrent neural networks, and how to build a convolutional neural network using the Keras library. The course material of this course is available free, but for a certificate, you have to pay. In this course, you will also learn how do neural networks learn and what are activation functions.

Andrew Yan-Tak Ng (Chinese: 吳恩達; born 1976) is a Chinese-American computer scientist and statistician, focusing on machine learning and AI. Also a business executive and investor in the Silicon Valley, Ng co-founded and led Google Brain and was a former Vice President and Chief Scientist at Baidu, building the company's Artificial Intelligence Group into a team of several thousand people. Ng is an adjunct professor at Stanford University (formerly associate professor and Director of its AI Lab). Also a pioneer in online education, Ng co-founded Coursera and deeplearning.ai. With his online courses, he has successfully spearheaded many efforts to "democratize deep learning."

I haven't taken this specific Udacity course on deep learning. But, I have completed their Nanodegree for the self-driving cars that covered a decent amount of deep learning material. I won't be surprised if they borrow some of the contents from there as well. Udacity offers high quality lectures and related projects. Their content is usually ver well organized and they are constantly improving.