A quick answer is that all cell groups are small groups but not all small groups are cell groups. Small groups can meet specific needs of the group members. Small groups have a history of benefiting the body of Christ especially in time of revival. Cell groups are a specific type of small group and a type of small group that has a specific model of ministry.
Most small groups are one of the programs offered by a church congregation.
Most basic unit Cell groups are not a program of the congregation. They are the most basic unit of the congregation. Cell groups are the smallest units of people who have teamed up to do the work of the congregation and the denomination. In a cell group, Christians come together in a covenant relationship to do the work of the kingdom. Cell members join with one another to accomplish four specific tasks.