An accordion menu is a list of headers that can be clicked to expose content. It's useful for progressively revealing information by highlighting the most important details and then empowering the users to cherry pick the content that is most relevant to their needs. This can help complex web pages seem less daunting and reduce the need for scrolling, making them great for mobile. However, while it does reduce the perception of complexity, it also increases the interaction cost by requiring users to decide on topics.
While accordions have their advantages, they also come with some drawbacks.
It's important to weigh out the pros and cons of accordions when considering them as a solution. They're most suitable if end-users only need a few pieces of content to complete their goal or task.