What technique is exemplified by Tommy's father's proverb about "putting all your eggs in one basket"?

The phrase "putting all your eggs in one basket" is an idiom. An idiom is a commonly used expression that conveys a meaning that is not deducible from the individual words. In this case, the proverb suggests that one should not focus all their resources or efforts in one area, as doing so can lead to significant loss if that particular effort fails.

Using idioms allows for conveying complex ideas in a relatable and memorable way. This particular idiom has become a standard part of the English language, illustrating a cautionary principle about risk management. It effectively uses the imagery of eggs in a basket to represent opportunities or investments, making it easier for people to understand the underlying message without needing to explain the literal meaning of each word.