This document discusses data accessibility and challenges. It covers the data life cycle, including planning, generating data, reliability, ownership, metadata, versioning, and publishing. It discusses expectations for accessing and sharing data. Open access data policies are encouraged by research funders, journals, and initiatives like DataCite to assign identifiers to research data. Data can be shared through repositories, journals, websites, or informally between researchers. Factors that affect sharing and accessing data include size, computing needs, standards, repositories, data nature, governance, and metadata.