Back:
2 USB 2.0 ports
2 USB 3.2 Gen 1 ports
1 Audio line-out port
1 HDMI 1.4b port
HDMI 1.4 (Maximum resolution supported over HDMI is 1920×1080 @60Hz. No 4K/2K output)
1 DisplayPort 1.4
1 RJ-45 Ethernet port
1 AC power supply port

Slots
Vostro 3 TPM:
1 PCIe x16 slot
2 PCIe x1 slots
1 M.2 2230 slot for WiFi and Bluetooth combo card
1 M.2 2230/2280 slot for a solid-state drive
2 SATA slots for 3.5-inch hard drive, 2.5-inch hard drive/solid-state drive
1 SATA slot for the optical drive
1 PCI-32 x1

Vostro 3 non-TPM:
1 PCIe x16 slot
1 PCIe x1 slot
1 M.2 2230 slot for WiFi and Bluetooth combo card
1 M.2 2230/2280 slot for a solid-state drive
2 SATA slots for 3.5-inch hard drive, 2.5-inch hard drive/solid-state drive
1 SATA slot for the optical drive