The By Medium reports under Universal Analytics reports demonstrate the Universal Analytics reports with respect to the different marketing mediums.
Guide to marketing mediums.
A. Navigate to: Performance AI ➡️ Google Analytics ➡️ Universal Analytics Reports ➡️ By
B. This will open the By Medium reports under Universal Analytics:
The first report is an Overview of all the visitors to your site in the specific time period:
a. The number of Sessions that people have on the site, in this case it's 32744, which is
12.41% less than the earlier period.
b. The number of New Users or people who have visited the website, in this case, it's
180189 people, which is 16.49% less than the earlier period.
c. The Bounce Rate or the rate at which new users leave your site without taking any
action, in this case, it was 36.7% while earlier it was 50%.
d. The Avg Session Duration or the average time a new user spent browsing the site, in
this case, was 02:44 Minutes, while the reference was 01:30 minutes.
e. The No. of Pages/Session refers to the average number of web pages a user visits when
they come to your website, in this case, it is 3.6, while the reference was 2.
This is followed by a set of tables, the first two are Sessions and New Users:
f. The total number of the parameters are depicted at the top, in this case, the total number
of Sessions is 327,447.
g. The 
symbol can be used to bring up the full table of contents for each of the
tables.
h. The referral medium caused 65790 sessions during the time period.
i. The referral medium accounted for 20.1% of the sessions during the time period.
j. The cpc medium accounted for 32043 new users coming in during the time period.
k. CPC medium accounts for 16.2% of the total new users during the time period.
This is followed by three tables titled Bounce Rate, Avg. Session Duration and Page
View per Session, in these cases, the big numbers at the top of the table depict the
average numbers for each of these parameters
l. The email medium bought in users who had a bounce rate of 39.4%.
m. The email medium accounted for 14.6% of the total sessions for the site.
n. The (none) source/medium bought in users who had an avg. session duration of
2:33 minutes.
o. The (none) source/medium accounted for 18.4% of the total sessions for the site.
p. The (none) source/medium bought in users who visited 3.4 pages per session.
q. The (none) source/medium accounted for 17.2% of the total sessions for the site.
Next:
How do I navigate to the By Source reports under the Universal Analytics reports?
How do I navigate to the By Channel reports under the Universal Analytics reports?
How do I navigate to the By Source/Medium reports under the Universal Analytics reports?