Lateness vs. Latency

Lateness

Meaning: The state of being late; delay in arriving or doing something.

Hindi: देर, विलंब

Examples: 

His lateness to the meeting annoyed everyone.

I apologize for my lateness.

Latency

Meaning: A delay before something begins or before a response is received.

Hindi: सुप्तावस्था; विलंब अवधि

Examples: 

The network has high latency.

Low latency is important for online gaming.