Final answer:
In an informative/explanatory article about party planning, concepts like the theme, invitation, and venue play critical roles in explaining the planning process, as they structure the entire event.
Step-by-step explanation:
In an informative/explanatory article about party planning, several concepts are typically used to explain the process to the reader. A theme is crucial as it sets the tone and direction for the party, allowing for coherent decoration and activities. An invitation is also central to explain because it conveys critical information about the event and is the first point of engagement with potential guests. The venue is essential to elaborate upon as it determines the logistics, such as capacity, location, and amenities, thereby shaping the event's feasibility and success. While a cake is a common element in parties, it is not necessarily explanatory for the overall planning process but rather a specific item that could be included within broader categories such as catering or menu planning. Therefore, when writing an informative article, the emphasis should be placed on broader organizational concepts like theme, invitation, and venue, which underpin the structure of the party planning process.