A more thorough explanation:

A transition phrase is a word or group of words that connects one idea to another in a sentence or paragraph. In a patent claim, it is the word or phrase that links the introduction to the main part of the claim.

In a patent claim for a new type of phone case, the transition phrase might be "comprising," "having," "including," "consisting of," or "consisting essentially of." For example, "A phone case comprising a shock-absorbing material and a waterproof coating."

This example shows how the transition phrase "comprising" connects the introduction (phone case) to the main part of the claim (shock-absorbing material and waterproof coating).

In a paragraph about the benefits of exercise, a transition phrase might be "Furthermore," "In addition," or "Moreover." For example, "Exercise has been shown to improve cardiovascular health. Furthermore, it can also reduce stress and improve mental health."

This example shows how the transition phrase "Furthermore" connects the idea of cardiovascular health to the additional benefits of exercise.