Maps that focus on ideas are known as

A thematic map

Explanation:

A thematic map is a learning tool based on the graphic representation of a certain topic through the schematization of the concepts that compose it. These concepts are written hierarchically within geometric figures such as ovals or boxes, which connect to each other through lines and link words. The use of concept maps allows you to organize and understand ideas in a meaningful way.

the answer is use of support  

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.