What does it mean for software to be intelligent?

Intelligent software definition: intelligent software refers to any application that uses artificial intelligence to analyze and interpret data, or communicate with systems and humans.

Explanation:

The thing that makes intelligent software intelligent is the ability to learn from examples.

In most of computer programming, you have expected inputs and outputs. A webpage asks for your email address, verifies that it looks like an email address, and lets you continue. When writing that email verifier, it is relatively easy to come up with a fixed set of rules that will tell you whether a string is a valid email.

But some problems are less tractable, and using a fixed set of rules would be incredibly difficult. For instance, imagine you want to write an app that can give an estimate of how much a house would sell for if placed on the market. It would take in a description of the house (3 BR, 2 BA, 2300 sqft, etc) and where it is located, and return an estimated sale price. You could write a few rules for this - some number of dollars per square foot, add some amount for the presence of a garage, etc. but it would be hard to take location into account. And current market trends. Special features of the house would all require special edge cases in the code.

Instead, you could write an algorithm that learns from past home sale data. It would look for patterns (like the price per square foot, etc) and take into account how much similar houses in similar locations during similar markets sold for. These patterns exist, but are noisy. Intelligent software excels at distilling the pattern from the noise and returning an estimate that may not be perfect, but on the average is fairly good.