When it comes to structuring the data on your website, there are two main options: Microdata and JSON-LD. Both formats are used to provide additional information about your website to search engines, but they have some key differences that can affect your SEO efforts.

Microdata is a set of tags that you can use to embed structured data into your website's HTML code. This structured data can include information such as product information, reviews, and event details. Microdata is supported by all major search engines, and can be used to create rich snippets in search engine results pages (SERPs).

JSON-LD, on the other hand, is a JavaScript-based format for structuring data. Instead of being embedded in the HTML code of a webpage, JSON-LD data is placed in a separate script tag, which makes it easier to implement and maintain. JSON-LD is also supported by all major search engines and can be used to create rich snippets in SERPs.

When it comes to which format is better for SEO, both Microdata and JSON-LD have their own advantages and disadvantages. Microdata can be more difficult to implement, especially for large websites, but it has better support for custom vocabularies and can be more easily read by search engines. JSON-LD, on the other hand, is easier to implement, but has less support for custom vocabularies.

In terms of ranking and visibility, using any kind of structured data can have a positive impact on your SERP visibility by creating rich snippets for your website. Rich snippets can help your website stand out in search results, making it more likely to be clicked on by users. Additionally, providing search engines with structured data can help them understand the content on your website better, which can lead to better search engine rankings.

In conclusion, both Microdata and JSON-LD are useful formats for structuring data on your website and both are supported by major search engines. Both can be used to create rich snippets and improve visibility in SERP. Ultimately, the choice of format will depend on your specific needs and the level of technical expertise available in your organization. It is recommended to consult with an SEO expert to make the best decision for your website.