It is a popular devotional chant (bhajan/ mantra) that summarizes key names and events from the Ramayana. Reciting it is believed to bring peace, protection, and blessings from Lord Rama.
Below are the English transliterated lyrics and their meanings, along with resources for further study. Aarti Shri Ramayan Ji Ki ramayan sumiran lyrics in english link
[Section 4] The final battle took place with Ravana, and Shri Rama killed him. Ravana's end came, and Shri Rama's character shone bright. It is a popular devotional chant (bhajan/ mantra)