Career transition from mechanical Engineering to Artificial Intelligence

Machine learning and Artificial intelligence been one of the best career's now. But when i'm working on six sigma after completion of mechanical engineering. 4 to 5 years back i came to know about machine learning, data science, artificial intelligence but doing to career transition 4 years back been pretty challenging very less resources and less understanding on what exactly data science? or what exactly machine learning? I can't figure out what exactly meant by machine learning algorithms,...