DataFrames in R are used to store tabular data with rows and columns. DataFrames can contain different data types in each column. They are created using the data.frame() function by passing vectors as arguments. Operations that can be performed on DataFrames include creating, accessing and selecting subsets of rows and columns, editing data, and adding or deleting rows and columns. The structure of a DataFrame can be examined using the str() function.

2.  DataFrames in R are generic data objects of R
which are used to store the tabular data. Data
frames can also be interpreted as mattresses
where each column of a matrix can be of the
different data types.

3. DataFrame is made up of three principal
components:
 the data
 rows
 columns.

4. Operations that can be performed on a DataFrame
are:
 Creating a DataFrame
 Accessing rows and columns
 Selecting the subset of the data frame
 Editing dataframes
 Adding extra rows and columns to the data frame
 Add new variables to dataframe based on
existing ones
 Delete rows and columns in a data frame

5. To create a data frame in R use data.frame() command and then
pass each of the vectors you have created as arguments to the
function.
Example:
# R program to create dataframe
# creating a data frame
friend.data <- data.frame(
friend_id = c(1:5),
friend_name = c("Sachin", "Sourav", "Dravid", "Sehwag“
, "Dhoni")
stringsAsFactors = FALSE
)
# print the data frame
print(friend.data)

6. Output:
friend_id friend_name
1 1 Sachin
2 2 Sourav
3 3 Dravid
4 4 Sehwag
5 5 Dhoni

7. Get the Structure of the Data Frame
 One can get the structure of the data frame
using str() function in R.
 Example:
# R program to get the
# structure of the data frame
# creating a data frame
friend.data <- data.frame(friend_id = c(1:5),
friend_name = c("Sachin", "Sourav",
"Dravid", "Sehwag", "Dhoni"),
stringsAsFactors = FALSE
)
# using str()
print(str(friend.data))

8.  OUTPUT:
'data.frame': 5 obs. of 2 variables:
$ friend_id : int 1 2 3 4 5
$ friend_name: chr "Sachin" "Sourav"
"Dravid" "Sehwag" ...
NULL