What does it mean for a virus to be an obligate intracellular parasite?

 A virus being an obligate intracellular parasite means that:

1. A virus can only reproduce inside a living host cell.
2. It cannot carry out metabolism, growth, or reproduction on its own.
3. Outside a host cell, a virus is inactive.

In simple terms

Viruses must hijack a host cell’s machinery to survive and make more viruses.

They use the host’s:

1. Ribosomes (to make viral proteins)
2. Enzymes
3. Energy (ATP)
4. Nucleotides

Without a host cell, a virus cannot replicate.