What is ameba and how does it move?

An amoeba is a single-celled animal that catches food and moves about by extending fingerlike projections of protoplasm. Amoebas are either free-living in damp environments or parasitic.

In the case of an amoeba moving, it's cytoplasm flows forward to form a pseudopodium, then it evens back out. In order to eat, it will form two pseudopodia and wrap those around to meet each other, enclosing its food, then the cytoplasm evens out again.