Wiki definition of ML

[Eddy]

Machine learning is a scientific discipline that is concerned with the
design and development of algorithms that allow computers to evolve
behaviors based on empirical data, such as from sensor data or
databases. A learner can take advantage of examples (data) to capture
characteristics of interest of their unknown underlying probability
distribution. Data can be seen as examples that illustrate relations
between observed variables. A major focus of machine learning research
is to automatically learn to recognize complex patterns and make
intelligent decisions based on data; the difficulty lies in the fact
that the set of all possible behaviors given all possible inputs is
too large to be covered by the set of observed examples (training
data). Hence the learner must generalize from the given examples, so
as to be able to produce a useful output in new cases. Artificial
intelligence is a closely related field, as are probability theory and
statistics, data mining, pattern recognition, adaptive control,
computational neuroscience and theoretical computer science.