Both tools allow you to extract data from most data sources. Both offer intuitive interfaces to make the connection and create data transformation process and complete pipelines. And with both you can load the data into a wide array of data destinations.
Talend offers a free, open-source version as well as an enterprise version that typically costs in the thousands of dollars per user. The main difference is that the enterprise version comes with support.
Informatica has PowerCenter Express, which is free but limited, and a Professional version, with per-user fees similar to that of Talend.