Describing the processes of metaphor comprehension has been a hot topic of discussion among researchers throughout the past four decades. One of the major challenges has been to find a mechanism that can describe the processes involved in the comprehension of various kinds of metaphors. This article suggests that different types of metaphors could be understood through rather different mechanisms. To demonstrate this point, two different groups of metaphors are discussed. The first group includes those metaphors that are used to describe highly abstract concepts. In many cases, these abstract concepts are understood in terms of motion or non-motion events in the three-dimensional space. The second group includes those metaphors which are used to describe concepts with a higher degree of... concreteness. In many cases, these metaphors are understood by attributing a salient feature of a metaphorical category to the topic of the metaphor. Because of their nature, the first group of metaphors can be understood in terms of a set of elements in a three-dimensional space. This can be done by the mapping of relations in the source domain into relations in the target domain. Therefore, this group of metaphors is understood through a more complex type of processing. However, degree of complexity of metaphor processing could be dependent on a range of factors, including the number of elements that are involved in the source and target domain, the nature of relations among elements in the source and target domains, degree of abstractness of the concept that is described by the metaphor, and semantic features of source and target domains.