Short answer is "Yes".
Long answer is "No":
As far as I am concerned the difference is limited to a specific author/lecture:
(to the best of my understanding of the slides)
The author of the linked slides does not want to refer to "search" as a technique like planning, but rather as a general procedure.
Planning is the process of finding a set of (valid) actions that transform an initial state (set of properties) to a goal state. Such a problem can be represented by a state space graph, where each node defines a complete world state (i.e. a set of properties). Two nodes are connected if there exists a valid action transforming one state into another.
- "Search" is the general procedure of finding a solution by searching the problem space. In this case it is the process of iterating a state space graph starting at the initial node, trying to find a path to the goal node, i.e., using DFS. The search problem is given an (perhaps implicit) representation of the graph and is not concerned about internal properties of nodes.
- A non-search "Planning" algorithm on the other side may make use of the logical properties of the states to iterate the state space graph.
However, I would like to note that most "Planning" algorithms do use some kind of search procedure on the state space graph, significantly improving the search using planning-heuristics:
Consider the graph given on slide 4 (of the referenced link). The complete graph represents the planning problem. The search "only sees" nodes and edges. A DFS would simply iterate all possible paths until a solution is found. A heuristic (planning algorithm) may use additional relations between properties (i.e. getting milk implies going to the supermarket first).
Informal definition of plan: the solution to a planning problem. A sequence of actions that translate the initial (world) state into the goal state.
In terms of the (graph) search this would be a list of edges to traverse. If there exists a valid plan, then there exists a path in the graph.
(this may be a little out of scope)
Since planning is in general PSPACE-complete naive search algorithms perform exceptionally bad on many instances. Common heuristics/techniques used in planning are based on the relaxation of the state space graph, i.e., by relaxing preconditions or effects (resulting in easier problems; in P, or NP) which can be solved "easily". If you are interested in planning that is somewhat separated from "search" you might wan to take a look at hierarchical task networks (HTN) which is basically planning with additional domain knowledge.