by the way~
A conjunction that shifts the topic of conversation to something new, often with a sense of wanting to ask or mention something else.
ところで is a discourse marker used when you want to change the subject completely. It's like saying 'by the way' or 'speaking of which' in English. You often use it when you remember something you wanted to ask or mention, but it's not directly related to what you were just talking about.
It's common in both casual and formal conversation, but it's not used in formal writing like essays or reports. You'll hear it in everyday chats, meetings, and even interviews. When you use it, it signals a clear shift, so avoid using it if you are just adding a small detail to the same topic.