Who was Samuel in the bible

Samuel was a Prophet and Judge of Israel who succeeded Eli. He was the last judge to rule before the advent of kingship.
The Israelites had asked to be ruled by kings instead of judges, God approved that he yield to their request and anoint Saul as king.
Samuel continued as judge over Israel all the days of his life. From year to year he went on a circuit from Bethel to Gilgal to Mizpah, judging Israel in all those places.
1 SAMUEL 7:15–16
Delivering good news does not seem to have been a part of Samuel’s job description very often. Yet he was so important to Israel’s history that he came to be known as a second Moses (see Jeremiah 15:1).
Like so many others in scripture – Isaac, Samson, and John the Baptist, for example, Samuel was a miracle baby. After pleading with God in the sanctuary at Shiloh, Samuel’s mother finally conceived. Hannah had promised that her firstborn son would be devoted to God’s service. True to her word, Hannah brought the young boy to Shiloh, where he served
under the care of Eli the priest.
Samuel’s first encounter with God required him to deliver unsettling news to Eli. God had spoken to Samuel, telling him that his mentor was about to be judged for his failure to restrain his wicked sons, who also served in the sanctuary.
Years later, the Israelites demanded that Samuel appoint a king. God told Samuel to grant the people’s request, and then He gave Samuel more bad news to deliver: Israel would come to regret the day they asked for a king. Kings had a way of oppressing their people, seizing their lands and taxing the fruits of their labors. Samuel’s prophetic words were fulfilled when Solomon’s greed wound up splitting the kingdom in two.
The first choice of king, a man named Saul, proved a disaster, giving Samuel the opportunity to deliver yet another dose of unwelcome news: Saul would not sit long on the throne, and none of his descendants would follow him. Even in death, Samuel delivered bad news for those who disobeyed the Lord. When a desperate King Saul consulted a medium (or witch) at Endor, the figure of Samuel appeared from beyond the grave, telling Saul that he would not live to see another.
Such was Samuel’s reputation that the elders of Bethlehem trembled when the elderly prophet arrived in their town. However, this time Samuel brought good tidings, guided by God, he anointed David to be Saul’s replacement.