1, with different usage:
Connection: mainly used to refer to the inanimate connection (physical) between objects, such as the connection between points in mathematics.
Connection: mainly used to refer to a nihilistic or spiritual connection, such as connected neurons.
Link: It has the same meaning as link, but it is mainly used to refer to the link of inanimate objects. Jinzhou, for example, is a strategic place connecting Northeast China and North China.
Connection: generally refers to the connection of two things with the same nature or appearance, such as the connection of parts and the connection of the Internet.
Link: a link is a link from one web page to another, which is mainly used to refer to logical combinations, such as hyperlinks and friendship links.
2, the scope of the definition is different:
Contact: including the meaning of contact and connection.
Contact: covers the meaning of contact, contact, combination, unity and combination.
Link: It covers the meanings of cohesion, association and association.
Connection: including connection, static connection and dynamic connection.
Link: It covers the meaning of cohesion and connection.
Extended data
Math books usually use "connection" or "connection", which is not recommended. In the past, there were two kinds of "connections" in junior high school mathematics, so when writing junior high school mathematics textbooks, it was customary to write line segment connections as "connections" to show the difference. So there is only one way to write "connection" in junior high school math books.