The measurement of flow harmonics of charged particles
from $v_2$ to $v_7$ in Pb+Pb collisions in the wide range of
transverse momentum and pseudorapidity provides not only a way to study the initial state of the nuclear collisions and soft particle collective dynamics, but also provides insight into jet quenching via the measurement of flow harmonics at high transverse momenta. The longitudinal fluctuations of $v_n$ and event-plane angles $\Psi_n$ are also presented. The
longitudinal flow decorrelations have contributions from
$v_n$-magnitude fluctuations and event-plane twist. A
four-particle correlator is used to separate these two
effects. Results show that both effects have a linear
dependence on pseudorapidity separation from $v_2$ to $v_5$,
and show a small but measurable variation with collision
energy. While collectivity is well established in collisions
involving heavy nuclei, its evidence in $pp$ collisions isless clear.
In order to assess the collective nature of multi-particle production, the correlation measurements are extended to include azimuthal correlations measured using
multi-particle cumulants. The measurements of multi-particle cumulants $c_2\{2-8\}$ confirm the evidence for collective
phenomena in $p$+Pb and low-multiplicity Pb+Pb collisions. For $pp$ collisions, the measurements of cumulants do not yet
provide clear evidence for collectivity as they are susceptible to event-by-event multiplicity fluctuations. A new modified cumulant method, which suppresses both the contribution of multiplicity fluctuations and non-flow
effects, is used to address this issue.