Samata meditation is to get tranquil, to get concentrated, to get calm. It can sharpen the mind a bit, and it can also go into psychic phenomena. If a person is Kammicly endowed, they might be able to develop psychic powers. These are all in Samata practice. It does not mean that you are going to end your anger, or your fear or your restlessness. There's not actually any purification of the mind done in Samata practice. It can be calming and very peaceful. It can also be a nice resting place. It can be exciting as well with physical phenomena, but it is not a purification part of the practice.
Vipassana meditation is the purifying coming from wisdom. We are trying to develop wisdom in order to let go of anger, fear, jealousy, and other unbeneficial qualities. With concentration practices, we can push things away if we are very well concentrated. We can keep things out of the mind, but it all comes back later. With Vipassana practice, hopefully we learn to let the unbeneficial qualities go while we are in the meditation and we are also able to let them go in our normal life. So that's the distinct differences.
Buddhism teaches both Vipassana and Samata meditation. If you do Vipassana, you do not have to do Samata. If you do Samata, you must also do Vipassana because it is only in the Vipassana work that we actually learn how to let go of all the Dukkha. The way that we teach Compassion/Lovingkindness and the Five Reflections is all Vipassana meditation. Now some of you may have been to other teachers, you may go to some in the future who teach something that looks like our Compassion/Lovingkindness meditation, but it depends on how they are teaching it whether it will be a Samata practice or whether it will be a Vipassana practice. As we do it here it is Vipassana practice.