Incorrect spelling, explanation: conection is incorrect, because n should be doubled, due to the prefix con- in the original Latin form connexare. Because two n’s met each other, they were doubled and this spelling remained in English form connection. Therefore connection is the correct form.

Correct spelling, explanation: this form is the correct one because connection comes from Latin connexare. Double n has already been there in original form. Moreover, the Latin word n must have been doubled due to combining two words (prefix con- and the word nectere). Therefore connection is the correct spelling, while conection is a mistake.

Definition of connection:
noun, attachment, or relationship
Sorry, I hung up, I lost the internet connection.
I just don’t seem to have a good connection with my brother.