Lead magnets are normally digital products such as eBooks or reports that are given away in exchange for an email address. 

Autoresponders are automated emails that get sent out once that email address is received. 

Tripwires are low cost items that convert leads into sales and generate new customers that can then go on to buy core products and services. 

Full post with more information, examples and details:

https://jamesbachini.com/lead-magnets-autoresponders-tripwires/