  Ti exhibits complex plastic deformation controlled by active dislocation and
twinning systems. Understandings on dislocation cores and twin interfaces are
currently not complete or quantitative, despite extensive experimental and
simulation studies. Here, we determine all the core and twin interface
properties in both HCP and BCC Ti using a Deep Potential (DP) and DFT. We
determine the core structures, critical resolved shear stresses and mobilities
of <a>, <c+a>, <c> dislocations in HCP and <111>/2 dislocations in BCC Ti. The
<a> slip consists of slow core migration on pyramidal-I planes and fast
migration on prism-planes, and is kinetically limited by cross-slips among
them. This behaviour is consistent with "locking-unlocking" phenomena in TEM
and is likely an intrinsic property. Large-scale DFT calculations provide a
peek at the screw <c+a> core and glide behaviour, which is further quantified
using DP-Ti. The screw <c+a> is unstable on pyramidal-II planes. The mixed
<c+a> is nearly sessile on pyramidal-I planes, consistent with observations of
long dislocations in this orientation. The edge and mixed <c+a> are unstable
against a pyramidal-to-basal (PB) transition and become sessile at high
temperatures, corroborate the difficulties in <c>-axis compression of Ti.
Finally, in BCC Ti, the <111>/2 screw has a degenerate core with average glide
on {112} planes; the <111>/2 edge and mixed dislocations have non-dissociated
cores on {110} planes. This work paints a self-consistent, complete picture on
all dislocations in Ti, rationalises previous experimental observations and
points to future HRTEM examinations of unusual dislocations such as the mixed
and PB transformed <c+a> cores.
