On the surface, attendance tracking and time tracking are different. The former, in its purest sense, tracks whether or not employees show up for work on a daily basis, whereas the latter tracks the exact hours (and sometimes the exact tasks) that they work on. However, you will find that most software systems have integrated these features together into comprehensive "time & attendance-tracking modules"that accomplish both purposes within the same interface.
Depending on the complexity of your business structure and work tasks, you may not need a complicated attendance tracking software solution. If you only need to track working days versus any type of leave, then something simple and cost-effective will likely do the trick. However, for most businesses, you'll likely want something with a bit more depth to it. More advanced features that are blended between attendance and time tracking software include detailed task tracking, billable versus non-billable hours, and advanced clocking in/out features (e.g., biometric, selfie, GPS, or geofencing).