The source is a transcript from The SDM Show, hosted by Rob Cairns of Stunning Digital Marketing, featuring guest Ricky Blacker from WP Engine. The central topic of their discussion is WordPress accessibility, specifically promoting the upcoming WP Accessibility Day on October 15th and 16th, which is a free, 24-hour global event. Cairns and Blacker discuss the crucial importance of designing websites to be accessible to everyone, not only for ethical and user experience reasons but also to avoid potential legal and financial issues such as class-action lawsuits. Blacker shares his journey into the WordPress space and emphasizes that accessibility should be a foundational consideration in website development rather than an afterthought, advocating for simple best practices like proper alt tags and contrasting colors. The conversation concludes with details about the conference's structure, which involves pre-recorded talks and live Q&A sessions using the Zoom platform.