I was referring to a datasheet where I found a capacitor is connected between two ground terminals. Are these really ground terminals or am I reading the datasheet in the wrong way? Can someone help me to understand what this part means is datasheet and why is this type of connection is used.
See the "Page 27" of the below datasheet
Reference datasheet: http://www.ti.com/lit/ds/symlink/lm3450.pdf?ts=1591116185629
Figure 1. The circuit has two grounds. The hollow ground symbol is used on the mains (live) side of the isolation. The solid ground symbol is used on the low-voltage DC side of the isolation.