What does each component in chain termination PCR do?

The components required to assemble chain termination PCR are: a sequencing primer, DNA template, dideoxynucleotides, a buffer, dideoxynucleotides, and DNA polymerase. 

• The DNA template is the DNA of interest, whose sequence has to be identified. The four deoxynucleotides (A,G,C,T) function as the monomers of DNA. 
• DNA polymerase is the enzyme responsible for building a DNA chain by adding deoxynucleotides. 
• The sequencing primer is a short DNA or RNA fragment that initiates the synthesis of a complementary strand during the sequencing reaction. It serves as a starting point for DNA polymerase. 
• Dideoxynucleotides are modified nucleotides lacking a 3'-OH group which prevents further elongation of the DNA chain when they are incorporated by DNA polymerase during replication.