While these words are very similar. There are some differences between them. When referring to dependence, the focus lays on a physical dependence on a substance. This is characterized by the symptoms of tolerance and withdrawal. According to the Addiction Center, it is possible to have a physical dependence without being addicted. However, addiction is typically right around the corner. With that being said, addiction is characterized by a change in behavior that is caused by the biochemical changes that occur in the brain after continued substance abuse. Substance use becomes the main priority of the addict, regardless of the harm they may cause to themselves or others. An addiction causes people to act irrationally when they don’t have the substance they are addicted to in their system.
I hope this helps you understand the difference between addiction and dependence.