( Incubation ( ( is ( ( the process ) ( of ( ( keeping ( ( the egg ) warm ) ) ( so ( ( the baby ) ( is ( protected ( while ( it ( 's developing ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Incubation)) (VP (VBZ is) (NP (NP (DT the) (NN process)) (PP (IN of) (S (VP (VBG keeping) (S (NP (DT the) (NN egg)) (ADJP (JJ warm))) (SBAR (IN so) (S (NP (DT the) (NN baby)) (VP (VBZ is) (VP (VBN protected) (SBAR (IN while) (S (NP (PRP it)) (VP (VBZ 's) (VP (VBG developing)))))))))))))) (. .)))
Incubation is the process of keeping the egg warm so the baby is protected while it's developing.
(ROOT (S (NP (NNP Incubation)) (VP (VBZ is) (SBAR (WHADVP (WRB when)) (S (NP (NNS birds)) (VP (VBP keep) (S (NP (PRP$ their) (NNS eggs)) (ADJP (JJ warm)) (SBAR (IN while) (S (NP (DT the) (NNS embryos)) (ADVP (RB inside)) (VP (VB develop))))))))) (. .)))
Incubation is when birds keep their eggs warm while the embryos inside develop.