Regarding group a column by another column and appending multiple columns

Hello sir, In project IMDB movie analysis, There are two questions as below. 1.Append the rows of all these columns and store them in a new column named Combined. 2.Group the combined column using the actor1name column. Doubt:Is appending is same as concatenate? how to group a column using another column. I have done concatenate and grouping is it correct or any other method i need to follow please let me know