According to MITRE, ATT&CK® is a globally-accessible knowledge base of adversary tactics and techniques based on real-world observations.
Techniques represent the 'how' an adversary achieves a tactical goal by performing an action, while tactics represent the "why" of a technique. Techniques are grouped by tactic to tell a story of both how an action was performed and why it was performed.
ATT&CK Map
The ATT&CK map for an analysis is displayed at the top of the Results page. This map displays the full capabilities of the Parent and all of the Children. Each technique has a link to the technique description on the MITRE website and an expandable tree which lists the samples in the analysis that implement the technique.
By default the map is displayed when navigating to the Results page though the default setting preference can be controlled in the Account Settings.