I use the term „meditation" on this website as a name for sitting comfortably and relaxed in any posture - and without any goal.
Meditation (or also: right concentration/concentration/absorption) is the eighth part of the Noble Eightfold Path of the Buddha. Meditation in Zen is called „sitting“ or „zazen“.
The word Insight is the name I use on this website for the technical terms "Kensho", "Satori" and "Dai Kensho" - also commonly referred to as enlightenment. Insight (or right insight) is the first part of the Buddha's Noble Eightfold Path.
Wikipedia: Right Knowledge (sammā diṭṭhi) is the insight into the Four Noble Truths of suffering, the origin of suffering, the extinction of suffering and the Eightfold Noble Path leading to the extinction of suffering.