Below are the some of the common difference in Package and Project Deployment.
Parameters are used in Project
Project deployment file will be .ispac file and the extenstion will be .dtsx
Project deployment will do in Integration Service Catalog
Packages are executed with T-SQL by using Parameters and environments set with T-SQL
Robust loggin is built in with several report
Package using the Configurations files and tables.
Package have the .dtsx extenstion.
Package are deployed in to the MSDB or FILE
CLR integration is not required.
Package deployment use the System Environment varibales.
Packages are executed with dtexe and dtexecui.