1. Release Cycle: CentOS is based on the Red Hat Enterprise Linux (RHEL) source code, receiving updates and patches at a slower pace since it aims for stability. In contrast, Slim is a rolling release distribution, meaning it continuously receives updates and doesn't follow a fixed release cycle.

2. Default Desktop Environment: CentOS by default does not come with a pre-installed desktop environment, making it ideal for server environments where a GUI is not necessary. On the other hand, Slim comes with a lightweight Xfce desktop environment, providing users with a graphical interface out of the box.

3. Package Management: The package manager used in CentOS is YUM (Yellowdog Updater, Modified), which is based on RPM packages. In comparison, Slim employs the Debian package manager (APT) along with the Synaptic Package Manager for software management.

4. Systemd vs Init: CentOS still predominantly uses the SysV init system for managing services and system initialization. Slim, in contrast, has adopted the modern systemd as its init system, providing additional features such as parallel startup of services.

5. Community Support: CentOS benefits from the strong backing of the Red Hat community and enterprise support, making it a preferred choice for businesses and enterprise environments. Slim, being a lightweight and community-driven distribution, relies more on community forums and resources for support.

6. Target Audience: CentOS is geared towards enterprise users and servers, emphasizing stability and long-term support. Slim, on the other hand, targets users who prefer a lightweight and customizable system for desktop or personal use.

In Summary, CentOS and Slim differ in release cycle, default desktop environment, package management, init systems, community support, and target audience, catering to distinct user needs and preferences.